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HomeMy Public PortalAboutR002 - Draft Master Drainage Report (60%) Final - AODADrainage Master Plan Town of The Blue Mountains Document Control 121076 Tatham Engineering Limited Town of The Blue Mountains 115 Sandford Fleming Drive, Suite 200 Collingwood, Ontario L9Y 5A6 32 Mill Street, Box 310 Thornbury, Ontario N0H 2P0 March 6, 2023 T 705-444-2565 tathameng.com Authored by: Reviewed by: DRAFT DRAFT Jacob Macdonald, B.A.Sc. Daniel Twigger, B.Sc.Eng., P.Eng. Engineering Intern Manager - Water Resources Engineering Disclaimer Copyright The information contained in this document is solely for the use of the Client identified on the cover sheet for the purpose for which it has been prepared and Tatham Engineering Limited undertakes no duty to or accepts any responsibility to any third party who may rely upon this document. This document may not be used for any purpose other than that provided in the contract between the Owner/Client and the Engineer nor may any section or element of this document be removed, reproduced, electronically stored or transmitted in any form without the express written consent of Tatham Engineering Limited. Issue Date Description 1 October 7, 2022 Draft 60% Submission 2 March 23, 2023 Final 60% Report Document Contents 1 Introduction .................................................................................................................................................... 1 1.1 Study Area ............................................................................................................................ 1 1.2 Background ........................................................................................................................... 1 1.3 Project Team ......................................................................................................................... 5 1.4 Master Planning Process – Approach #2 .............................................................................. 5 1.5 Existing Policies and Guidelines ........................................................................................... 8 2 Problem/Opportunity Statement ............................................................................................................. 15 2.1 Problem Statement ............................................................................................................. 15 2.2 Watershed/Drainage Area Specific Problems ................................................................... 15 2.3 Opportunity Statement ...................................................................................................... 19 3 Project Environment ................................................................................................................................... 21 3.1 Physical Environment ......................................................................................................... 21 3.2 Natural Environment ........................................................................................................... 26 3.3 Social Environment ............................................................................................................. 28 3.4 Cultural/Archaeological Environment ............................................................................... 29 3.5 Economic Environment ...................................................................................................... 30 4 Existing Conditions System Analysis....................................................................................................... 32 4.1 Existing Drainage Systems ................................................................................................. 32 4.2 Minor Drainage System Analysis ........................................................................................ 32 4.3 Major Drainage System Analysis ........................................................................................ 35 4.4 Drainage System Deficiency Identification ........................................................................ 39 4.5 Climate change Analysis..................................................................................................... 47 5 Future Conditions System Analysis ........................................................................................................ 48 5.1 Analysis Methodology ........................................................................................................ 48 5.2 Hydrologic Analysis ............................................................................................................ 49 6 Description of Overall Improvement Alternatives ................................................................................ 53 6.1 Existing Conditions ............................................................................................................. 53 6.2 Flow Reduction/Water Quality Improvements ................................................................. 53 6.3 Conveyance Capacity Improvements ................................................................................ 55 7 Public Consultation - Public Information Centre (PIC#1) .................................................................... 58 7.1 Notice of Study Commencement and Public Information Centre..................................... 58 7.2 Results of Public Consultation ............................................................................................ 58 7.3 Identified Drainage Issues & Concerns ............................................................................... 58 7.4 Public Preference ................................................................................................................ 59 7.5 Private Property Drainage Issues ....................................................................................... 59 8 Screening of Improvement Alternatives ................................................................................................. 61 8.1 Existing Conditions ............................................................................................................. 61 8.2 Flow Reduction/Water Quality Improvements ................................................................. 61 8.3 Conveyance Capacity Improvements ................................................................................ 76 9 Individual Drainage Projects Assessment and Evaluation .................................................................. 80 9.1 Watercourse 55 .................................................................................................................. 95 9.2 Boulder Channel (Watercourse 56) ................................................................................. 100 9.3 Little Beaver River ............................................................................................................ 101 9.4 Elgin Street North ............................................................................................................. 108 9.5 Beaver River ...................................................................................................................... 109 9.6 Watercourse 42 ................................................................................................................ 111 9.7 Watercourse 52 ................................................................................................................ 112 9.8 Watercourse 41 ................................................................................................................ 118 9.9 Watercourse 34 ................................................................................................................ 120 9.10 Watercourse 32 ................................................................................................................ 125 9.11 Watercourse 31 ................................................................................................................ 128 9.12 Outlet 30 ........................................................................................................................... 132 9.13 Watercourse 28 ................................................................................................................ 134 9.14 Outlet 26 ........................................................................................................................... 134 9.15 Outlet 25 ........................................................................................................................... 136 9.16 Outlet 24 ........................................................................................................................... 138 9.17 Outlet 23 ........................................................................................................................... 139 9.18 Watercourse 22 ................................................................................................................ 141 9.19 Watercourse 21 ................................................................................................................ 142 9.20 Watercourse 19 ................................................................................................................ 145 9.21 Watercourse 15 ................................................................................................................ 147 9.22 Watercourse 14 ................................................................................................................ 150 9.23 Outlet 13 ........................................................................................................................... 155 9.24 Watercourse 10 ................................................................................................................ 156 9.25 Watercourse 9 .................................................................................................................. 161 9.26 Watercourse 7 .................................................................................................................. 162 9.27 Drainage Act Improvements ............................................................................................ 163 9.28 Watercourse 6 .................................................................................................................. 165 9.29 Watercourse 2 .................................................................................................................. 181 9.30 Watercourse 1 .................................................................................................................. 182 9.31 Silver Creek ....................................................................................................................... 186 10 Preliminary Preferred Solution / Individual Drainage Projects ........................................................ 198 10.1 General Recommendations .............................................................................................. 198 10.2 Individual Drainage Solutions (Projects) .......................................................................... 201 10.3 Summary of Preliminary Preferred Solutions ................................................................... 214 11 Next Steps .................................................................................................................................................. 216 11.1 Public Consultation - Public Information Centre (PIC #2) ............................................... 216 11.2 Implementation Plan ......................................................................................................... 216 11.3 Policy Framework ............................................................................................................. 217 11.4 Master Drainage Report (100%) ........................................................................................ 218 Tables Table 1: Flood Frequency Design Guidelines for Road and Driveway Crossings .......................... 8 Table 2: Summary of Private Properties within the Flood Inundation Extents ............................ 21 Table 3: Existing Conditions Minor Drainage System Model Peak Flow Summary ...................... 33 Table 4: Existing Conditions Major Drainage System Model Peak Flow Summary ...................... 35 Table 5: Existing Conditions Total Flow Reduction/Redistribution Summary ............................. 38 Table 6: Existing Conditions Storm Sewer Deficiency Summary ................................................. 40 Table 7: Existing Conditions Maintenance Hole Surcharge Deficiency Summary ........................ 41 Table 8: Existing Conditions Bridge/Culvert Crossings Deficiency Summary ............................. 42 Table 9: Existing Conditions SWMF Water Quantity Assessment Summary ............................... 43 Table 10: SWMF Water Quality Assessment Summary ................................................................ 45 Table 11: Maximum Residential Lot Coverage and Imperviousness Summary ............................ 49 Table 12: Future Conditions Major Drainage System Model Peak Flow Summary ...................... 50 Table 13: Summary of Respondents’ Preferred improvement Options ....................................... 59 Table 14: Existing SWMF Retrofit/Expansion Pre-Screening Summary ...................................... 63 Table 15: Existing SWMF Pre-Screening Results Summary .......................................................... 67 Table 16: SWMF Creation Opportunity Pre-Screening Summary ................................................ 67 Table 17: SWMF Creation Opportunities Pre-Screening Results Summary ................................. 70 Table 18: Expansion Floodplain Storage Areas Pre-Screening Summary .................................... 70 Table 19: Linear LID Flow Reduction Results Summary for Select Watersheds .......................... 75 Table 20: Individual Project Evaluation Summary ......................................................................... 81 Table 21: Current List of Drainage Outlets Inspected and Maintained by The Town ................ 200 Table 22: Preliminary Preferred Individual Projects Summary ................................................... 202 Table 23: Project Costs Summary – Preliminary Preferred Solution .......................................... 214 Table 24: Property Acquisition Summary – Preliminary Preferred Solution .............................. 215 Figures Figure 1: Study Area Location Plan ................................................................................................. 2 Figure 2: Watershed Map ................................................................................................................. 3 Figure 3: Town of The Blue Mountains Official Plan Schedule ‘B-1’ ............................................. 24 Figure 4: Town of The Blue Mountains Official Plan Schedule ‘B-2’ ............................................. 25 Figure 5: Drawings 7A-7H: Alternative Solutions Maps ................................................................ 87 Figure 6: Drawings 8A-8H: Preliminary Preferred Solutions Maps ............................................. 206 Appendices Appendix A: Existing Conditions Report Appendix B: Background Appendix C: Fluvial Geomorphology Study Appendix D: Natural Heritage Study Appendix E: Stage 1 Archaeological Assessment Appendix F: Future Conditions Analysis Appendix G: Public Information Centre 1 Appendix H: Conceptual Design Drawings Appendix I: LID Design Drawings and Analytical Results Appendix J: Construction Cost Estimates Appendix K: Alternative Solutions Digital Model Files 1 Introduction Tatham Engineering Limited (Tatham) has been retained by the Town of The Blue Mountains (Town) to complete a Drainage Master Plan (DMP) following Approach #2 of the Master Planning process outlined in the Municipal Engineering Associations (MEA) Municipal Class Environmental Assessment Document (October 2000, as amended in 2007, 2011 and 2015). This Drainage Master Plan is a broad level assessment detailing the drainage deficiencies identified in the study area. It considers improvement alternatives to address the drainage deficiencies and completes an evaluation of these alternatives to establish a preferred alternative solution(s) to be implemented moving forward. Approach #2 involves the preparation of a Master Plan document at the conclusion of Phases 1 and 2 of the Municipal Class EA process fulfilling the requirements for Schedule B projects. 1.1 STUDY AREA The study area encompasses the entire Town of The Blue Mountains with a primary focus on the settlement areas of Lora Bay, Thornbury and Clarksburg, Camperdown, Craigleith and the Blue Mountain Village area. The general boundaries are Christie Beach Road to the west, Grey Road 21 to the east and Georgian Bay to the north as illustrated on the Study Area Location Plan (Figure 1) and Watershed Map (Figure 2) provided overleaf. The hydraulic analysis extends to the approximate settlement area boundary in the Town and includes the Town’s existing storm sewer, watercourses, culverts, bridges and outfalls. The hydrologic analysis encompasses the entire drainage area contributing to the conveyance features included in the hydraulic analysis. 1.2 BACKGROUND 1.2.1 Drainage Master Plan Existing Conditions Report (Tatham, October 2022) As part of Task 3 of this Drainage Master Plan, Tatham previously completed a n Existing Conditions Report summarizing the development of the minor and major drainage system hydrologic and hydraulic models and the drainage deficiencies identified through the models. The Existing Conditions Report identified deficiencies throughout the entirety of the study area described above. The existing conditions report is enclosed in Appendix A for reference. /...7 / ., IY 1 1 ' 1. N GEORGIAN BAY / ...., ..44. .. . ......... ,,. 1 ' 1 1 1 ' 1 1 r TOWN OF A M EA FO RD '%// TOWN OF COLLINGWOOD j /- r' i j ' / 7 I' i • TOWN OF THE BLUE MOUNTAINS ./ MUNICIPALITY OF GREY HIGHLANDS 0 2.5 5 10 15 20 I LEGEND WATERCOURSE HYDRAULIC MODEL LIMITS �f� BEAVER RIVER WATERSHED :::: DRAINAGE CATCHMENT BOUNDARY - ROAD CI MUNICIPAL BOUNDARY SETTLEMENT AREA BOUNDARY Kilometers v li T ,�"� T H ,h, I A, /\ I j° -G I /R j N G TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN FIG: 1 STUDY AREA LOCATION PLAN SCALE: 1:75,000 DATE: NOV 2021 DRAWN: KKS 2 n s LEGEND WATERCOURSE HYDRAULIC MODEL LIMITS = WATERSHED BOUNDARY QQ WATERSHED NO. — ROAD o MUNICIPAL BOUNDARY SETTLEMENT AREA BOUNDARY Kilometers r N ERING TA T HA M TOWN OF THE BLUE MOUNTAINS MASTER DRAINAGE PLAN WATERSHED MAP FIG: 2 SCALE: 1:35,000 DATE: NOV 2021 DRAWN: KKS 1.2.2 Thornbury West Drainage Master Plan (Tatham, March 2019) The Town of The Blue Mountains also previously invested in the preparation of the Thornbury West Drainage Master Plan (TWDMP) which identified drainage deficiencies, evaluated alternative solutions, and recommended preferred solutions for implementation in the Thornbury West study area. The TWDMP followed Approach #2 of the Municipal Engineers Association (MEA) Municipal Class Master Planning Process outlined in the Environmental Assessment Document. Through the TWDMP, several drainage projects were recommended including flow reduction / water quality improvements, minor system conveyance capacity improvements and major system conveyance capacity improvements as illustrated on the Preferred Alternative Solution Plans (Figures C and D) enclosed in Appendix B for reference. 1.2.3 Lora Bay Development SWM Pond No. 1 Stormwater Management Report (Tatham, December 2021) Tatham previously completed, and submitted to the MECP, a Stormwater Management Report in support of an ECA application for the existing stormwater management facility known as SWM Pond No. 1 to address the water quantity and quality controls of the entire watershed draining to SWM Pond No. 1. This SWMF services the Lora Bay development lands at the west end of the Town. Through the assessment of the SWM Pond No. 1 drainage system, several drainage projects were recommended along Boulder Channel to improve the major drainage system conveyance capacity to resolve existing deficiencies as also support future developm ent. The recommended improvements are illustrated on Preliminary Improvement Plans (Drawings IMP-1 – IMP-4) enclosed for reference. 1.2.4 Regional Stormwater Management Plan – Blue Mountain Diversion Drain – Drainage Act Assessment Report (WT Infrastructure, March 2022) As part of development in the Craigleith Area, there is a desire to address drainage at the base of the escarpment, in particular for Watercourse 7, Outlet 8, and Watercourse 9 from Lakeshore Road East to Georgian Bay. WT Infrastructure previously prepared a Drainage Act Assessment Report to conduct a complete peer review of the drainage strategy proposed by Crozier Consulting Engineers (Crozier) to address existing flooding conditions and allow for future development of lands in the Craigleith Area. The drainage strategy proposed by Crozier is illustrated on the Watercourse 7, 8, 9 Regional SWM Proposed Works (Drawing Fig 1B) enclosed in Appendix B for reference. 1.2.5 Clarksburg Ice Management Study for Grey Sauble Conservation Authority (CCL/IBI Group, May 2005) Several previous studies have been completed concerning the frequent ice jams in the Beaver River which have contributed to flooding in Clarksburg. The Clarksburg Ice Management Study summarizes the findings of the preceding studies and additional field investigations and hydraulic assessment completed as part of the 2005 study. Tatham has reviewed the Clarksburg Ice Management Study but has not undertaken an assessment of the ice jam issues in the Beaver River as this item is outside the scope of the Drainage Master Plan. 1.3 PROJECT TEAM The project team responsible for input and preparation of this report and the supporting documentation is comprised of the following: ▪ Town of The Blue Mountains (Town); ▪ Tatham Engineering Limited (Tatham) – Engineering; ▪ Grey Sauble Conservation Authority (GSCA); ▪ Nottawasaga Valley Conservation Authority (NVCA); ▪ Birks Natural Heritage Consultants Inc. (Birks) – Natural Heritage; ▪ Archeoworks Inc. (AW) – Archaeological; and ▪ Water’s Edge Consulting (WEC) – Fluvial Geomorphology. 1.4 MASTER PLANNING PROCESS – APPROACH #2 Approach #2 of the Master Planning process involves the preparation of a Master Plan document at the conclusion of Phases 1 and 2 of the Municipal Class EA process. The Master Plan document is to be made available to the public and interested stakeholders for review and comment prior to adoption by the Town. Following Approach #2, the Master Plan satisfies the Municipal Class EA requirements for Schedule B projects allowing these projects to proceed directly to Phase 5 of the EA process and detailed design by way of a Notice of Study completion. The Master Plan is a broad level assessment thereby requiring more detailed investigations at the project specific level for Schedule C projects recommended in the study in order to fulfil the requirements of the Municipal Class EA. As such, the Master Plan document becomes the basis for, and is used in support of, future detailed investigations for the specific Schedule C projects. After the completion of the Master Plan, Schedule C projects are required to fulfil Phases 3 and 4 prior to completing the Environmental Study Report (ESR) for public review. Master Plans are long-range plans that integrate infrastructure requirements for existing and future land uses with environmental assessment planning processes. Master Plans consider all aspects of the environment: physical, natural, social, cultural and economic, and involves consultation with the public, affected parties and review agencies throughout the process. This Master Drainage Plan for the Town of The Blue Mountains is proceeding through Phases 1 and 2 of the Class EA process (provided overleaf) as follows: ▪ Phase 1: Identify the Problem. ▪ Phase 2: Identify and assess, at a strategic level, alternative solutions to the identified problem, then recommend the preferred master plan that can be implemented as separate subsequent projects. The Master Drainage Plan will be finalized upon the conclusion of Pha ses 1 and 2 of the Class EA process and made available for public comment prior to being approved and adopted by the Town. Notice of completion to review agencies & public Discretionary public consultation to review preferred design If no order*, may proceed Opportunity for order* request to Minister within 30 days of notification 1.5 EXISTING POLICIES AND GUIDELINES This Existing Conditions Report and this 60% Drainage Master Plan has been prepared recognizing the policies, regulations and guidelines relevant to drainage infrastructure. Summaries of these documents and key considerations for the DMP are provided as follows. 1.5.1 The Blue Mountains’ Stormwater Management System Design Criteria for Thornbury West Stormwater Drainage Master Plan EA (2017) and Engineering Standards (2009) The Blue Mountains’ Stormwater Management System Design Criteria for Thornbury West Stormwater Drainage Master Plan EA provides direction for the effective management of stormwater in the Town recognizing the impact of snowmelt and climate change. This document was previously provided to Tatham for the Thornbury West Stormwater Drainage Master Plan project to supplement and supersede, where applicable, the Town’s Engineering Standards. These documents provide uniform minimum standards and policies for the planning and design of stormwater infrastructure. The documents include the Town’s policies and guidelines regarding environmental protection (water quality, water quantity, etc.), natural hazards (flood and erosion hazards), stormwater management facility (SWMF) design, and urban design concepts. Generally, these guidelines include the mandates of other policies, regulations and guidelines discussed in this section. As such, these guidelines act as the basis for the assessment of drainage deficiencies in the study area. As per the Town’s criteria, the minor drainage system (storm sewer) shall be designed to convey the 1:5-year (minimum) return frequency design storm peak flow. Road culvert crossings and road elevations shall be designed to satisfy the following design criteria: Table 1: Flood Frequency Design Guidelines for Road and Driveway Crossings ROAD CLASSIFICATION DESIGN FLOOD FREQUENCY Arterial 1:100-year Local and Collector 1:25-year Private Roads and Driveways 1:5-year 1.5.2 Stormwater Management Planning and Design Manual (2003) The Stormwater Management Planning and Design Manual evolved from the Ministry of the Environment, Conservation and Parks (MECP) Stormwater Quality Best Management Practices manual (June 1991) in response to evolving stormwater management practices to provide an integrated approach to effective stormwater management planning and design focused on water quality, water quantity and erosion control. The Planning and Design Manual is a tool, not a rulebook, providing guidance for the effective design of lot le vel, conveyance, and end-of-pipe stormwater management practices. The objectives of the Planning and Design Manual are to apply an integrated treatment train approach to manage stormwater and maintain the hydrologic cycle, protect water quality and prevent increased erosion and flooding. In accordance with the Town’s guidelines and Ontario Regulation 219/09, all new development and SWMF’s shall provide as a minimum Enhanced Level water quality control as specified in the Stormwater Management Planning and Design Manual unless it can be demonstrated to the satisfaction of the Director (MECP) that it is impractical to achieve this level of protection. 1.5.3 GSCA Policies for the Administration of the Development, Interference with Wetlands and Alterations to Shorelines and Watercourses Regulation The Grey Sauble Conservation Authority (GSCA) has a number of policy objectives including the protection of public health and safety, prevention of property damage and prevention of social disruption caused by natural hazards, and conservation, protection and management of natural resources within the Grey Sauble watershed. The GSCA administers the Development, Interference with Wetlands and Alterations to Shorelines and Watercourse Regulation (Ontario Regulation 151/06) under Section 28 of the Conservation Authorities Act. Deve lopment within the GSCA Regulation Limits is subject to GSCA review and approvals allowing the GSCA to ensure development proposals have regard for existing natural hazards. The Policies provide direction on land use and development considering natural hazards, natural heritage features, and the natural environment to protect public health and safety and to prevent property damage and social disruption. 1.5.4 NVCA Natural Hazards Technical Guide The Nottawasaga Valley Conservation Authority (NVCA) has prepared guidelines to assist consulting firms and municipalities in the review of technical reports in support of new development. The NVCA policy objectives include the protection of public health and safety, prevention of property damage and prevention of social disruption caused by natural hazards and conservation, protection, and management of natural resources within the Nottawasaga Valley watershed. The NVCA administers the Development, Interference with Wetlands and Alterations to Shorelines and Watercourse Regulation (Ontario Regulation 151/06) under Section 28 of the Conservation Authorities Act. Development within the NVCA Regulation Limits is subject to NVCA review and approvals allowing the NVCA to ensure development proposals have regard for the existing natural hazards. The Policies provide direction on land use and development considering natural hazards, natural heritage features, and the natural environment to protect public health and safety and to prevent property damage and social disruption. 1.5.5 Town of The Blue Mountains Official Plan (2016) The Official Plan (OP) outlines the goals, objectives and policies for land use and development within the Town of The Blue Mountains. The OP provides the Town direction for controlling growth, implementing by-laws and making public and private development decisions as a means of ensuring a healthy community. The OP provides guidance for land use changes, municipal initiatives and the provision of public works. As such, the OP provides policies for th e effective management of stormwater. The OP requires that all major commercial, industrial, institutional and residential development are supported by a SWM Report that shall: ▪ Provide recommendations on a stormwater quantity system which ensures that post - development run-off rates will not be greater than the pre-development run-off rates for storms up to and including the 1:100-year flood and the Regional Storm flood; ▪ Document the possible impacts of development on watershed flow regimes including their interconnection with groundwater resources; ▪ Provide recommendations on how to maintain pre-development water quality and improve run-off where appropriate; ▪ Document the means by which stormwater volume control will be provided; ▪ Provide a design that considers recreational amenity opportunities; and ▪ Determine and describe the necessary measures required to be undertaken during construction to mitigate potential negative impact of development. Where applicable, the alternatives for this project will consider the OP’s goals, objectives and policies. 1.5.6 Low Impact Development Stormwater Management Planning and Design Guide (2010) The Credit Valley Conservation Authority (CVC) and Toronto and Region Conservation Authority (TRCA) developed the Low Impact Development Stormwater Management Planning and Design Guide which speaks to the importance of at source SWM controls versus typical end-of-pipe facilities. The advantages of the LID approach include: ▪ Reduction in overall runoff volume; ▪ Reduction in phosphorus discharge; and ▪ Reduced long term operation and maintenance. As such, implementing LID measures where feasible will help reduce flooding and improve the overall water quality of the watershed. On this basis, all future development should evaluate the use of LID development principles as part of the SWM design. 1.5.7 Provincial Policy Statement (2020) The 2020 Provincial Policy Statement provides policy direction on matters of provincial interest regarding land use planning and development. This statemen t supports the protection of public health and safety, the natural environment and the resources of provincial interest while providing for appropriate development. The policy identifies the natural and built features to be protected and the areas where development and site alteration are restricted. Key requirements of this policy are as follows: ▪ Development and site alterations are restricted on lands within or adjacent to natural heritage features unless it is demonstrated that the natural features and their ecological function are not negatively impacted; ▪ Planning authorities shall take measures to protect, improve or restore the quality and quantity of water within watersheds, ground water features, hydrologic functions, natural heritage features and areas, and surface water features; ▪ Development and site alteration are restricted on lands adjacent to sensitive surface water and groundwater features unless mitigative measures or alternative development approaches protect these natural features; and ▪ Significant built heritage features are to be conserved. 1.5.8 Natural Hazard Policies The Natural Hazard Policies under the Provincial Policy Statement provide direction on land use and development in areas where there is a risk to public health and safety or a risk of property damage from flooding and/or erosion hazards. The Natural Hazard Policies aim to reduce the long-term risk to public health and safety or property damage through land management and by directing development outside hazardous lands. The natu ral hazards lands are defined in the Town’s Official Plan. 1.5.9 Lakes and Rivers Improvements Act (LRIA) The Lakes and Rivers Improvements Act is administered by the Ministry of Northern Development, Mines, Natural Resources and Forestry (MNDMNRF) for the purpose of managing, protecting, and preserving the use of the water of the lakes and rivers of Ontario and the land under them. The purpose of the LRIA is to provide for: ▪ The protection and equitable exercise of public rights in or over the waters of the lakes and rivers of Ontario; ▪ The protection of the interests of riparian owners; ▪ The management, perpetuation and use of the fish, wildlife and other natural resources dependant on the lakes and rivers; ▪ The protection of the natural amenities of the lakes and rivers and their shores and banks; and ▪ The protection of persons and of property by ensuring that dams are suitably located, constructed, operated and maintained and are of an appropriate nature. Approvals must be obtained from the MNDMNRF under the LRIA for the following: ▪ Dams; ▪ Watercourse crossings (bridges, culverts and causeways) where the drainage area for the watershed upstream of the crossing is greater than 5 km2 unless construction is being undertaken by a Provincial Ministry or municipality, or contractors employed by a Provincial Ministry or municipality on lands owned by the Crown or the municipality undertaking the construction; ▪ River channels (channelization of rivers, including dredging, diverting or enclosing a channel except for the installation or maintenance of a drain subject to the Drainage Act) where channelization of a river or stream may harmfully alter fish habitat, or impede the movement of fish in a river, stream or lake. Where the potential impact of channelization work on fish habitat and/or fish movement is unknown, such impacts must be confirmed with the Department of Fisheries and Oceans (DFO) or their delegate in consultation with the MNDMNRF. Where it is determined that proposed work will adversely affect fish habitat and/or impede the movement of fish an LRIA approval is required; ▪ Enclosures (river or stream enclosures) that enclose a length of watercourse greater than 20 m and may harmfully alter fish habitat or impede fish movement; ▪ Buried pipelines and cables where they hold back, forward or divert water; and ▪ Municipal and other drains. 1.5.10 Habitat Protection Provisions of the Fisheries Act The habitat protection provisions are in place to address threats to fish from habitat loss/degradation and changes to natural flow regimes. The habitat protection provisions prohibit the carrying on of a work, undertaking or activity that results in serious harm to fish that are part of or support a commercial, recreational or Aboriginal fishery. Serious harm to fish is considered the death of fish or permanent alteration to, or destruction of, fish habitat including spawning grounds and any other area, including nursery, rearing, food supply and migration areas, on which fish depend directly or indirectly in order to carry out their life processes. The habitat protection provisions are administered by the DFO under the Fisheries Act. Proposals that cause serious harm to fish are subject to review and approval by the D FO under the Fisheries Act. The DFO requires the proponent of projects near water to undertake a self - assessment to determine if a DFO review is required. For those projects that cannot avoid serious harm to fish or is likely to contravene one of the Species at Risk Act prohibitions with respect to aquatic species, and does not satisfy the DFO exemption criteria, then a DFO review is required. Waterbodies that do not require a DFO review are as follows: ▪ Approved marine disposal or dumping sites; ▪ Artificial waterbodies that are not connected to a waterbody that contain fish at any time during any given year, such as private ponds, commercial ponds, stormwater management facilities, irrigation ponds or channels, agricultural drains and drainage ditches, road side drainage ditches, quarries and aggregate pits; and ▪ Any other waterbody that does not contain fish at any time during any given year and is not connected to a waterbody that contains fish at any time during any given year. 1.5.11 Ministry of Transportation Highway 26 is a provincial highway owned and maintained by the Ontario Ministry of Transportation (MTO). As such, the MTO is responsible for the major drainage system culvert crossings under Highway 26. Through the Town of The Blue Mountains, Highway 26 acts as a barrier to flow on several watercourses. A number of the existing culvert crossings do not have capacity to convey the expected flows under Highway 26 causing backwater conditions upstream. The backwater conditions lead to flows spiling between watercourses upstream of Highway 26 at many locations throughout the Town. The MTO provides drainage design criteria and standards specific to MTO roads which must be considered when contemplating drainage improvements to Highway 26 within the Town. Key resources provided by the MTO are the Drainage Management Manual, the Highway Drainage Design Standards and the online IDF Curve Lookup tool. For the design and analysis of Highway 26 culvert crossings, the MTO standards for Rural Arterial roads are as follows: ▪ 1:25-year design storm peak flow for spans less than 6 m; and ▪ 1:50-year design storm peak flow for spans greater than 6 m. 2 Problem/Opportunity Statement The Problem and Opportunity Statements for this Drainage Master Plan are critical to demonstrate the need for the study and define an appropriate scope. These statements are provided in the following sections. 2.1 PROBLEM STATEMENT Currently, portions of the Town experience flooding during both minor and major storm events. Frequent flooding of private and municipal property during minor and major storm events has been documented throughout the Town along several of the watercourses due to insufficient drainage system capacities. The flooding has caused historic damage to both private and municipal property and causes concern for public safety. Also, there is significant erosion along a number of the channel reaches in the Town that threaten both private and municipal property and also causes concern for public safety. In addition to flooding, the existing storm infras tructure is reaching its service life expectancy and deteriorating. A majority of the aging storm sewers are undersized considering historic rainfall data and current climate models predict future increases in rainfall intensities and volumes. In some locations, municipal storm infrastructure is located on private property outside the municipal right-of-way making it difficult to access and maintain. Also, there are areas absent of minor drainage systems and stretches of deficient overland flow routes acros s the Town. Development, intensification, urbanization and growth in the Town have also adversely impacted the stormwater quality and ecological health of the various creeks and Georgian Bay. The culmination of the above noted factors results in a storm system that does not satisfy the Town’s engineering and development standards. 2.2 WATERSHED/DRAINAGE AREA SPECIFIC PROBLEMS Several existing problem areas have been identified through review of the available background information and previous stormwater studies and through consultation with Town staff and the general public. These problem areas are summarized in the following sections. 2.2.1 Town Wide Issues ▪ Many drainage outlets and watercourse outlets to Georgian Bay across the Town are located on private property, restricting the Town’s ability to maintain these outlets and their conveyance capacity. ▪ Due to high water levels in Georgian Bay over the past several years, many drainage systems and watercourse outlets have been damaged, partially or c ompletely obstructed, or lost to wave action. These outlet deficiencies reduce the capacity of drainage systems and can result in flooding of areas upstream and adjacent to the outlets. More detail will be provided in the following sections for significant outlet deficiencies. ▪ Culvert crossing deficiencies have been identified throughout all watersheds. More detail will be provided in the following sections for significant culvert crossing deficiencies. 2.2.2 Lora Bay Settlement Area ▪ A lack of an overland flow route along East Ridge Drive results in water ponding to significant depths and flooding of private property during major storm events. ▪ Minor drainage deficiencies and a lack of a sufficient minor drainage system along Lake Drive result in flooding of Lake Drive and private property during major storm events. ▪ An obstruction of the storm sewer outlet for the High Bluff Lane and Timber Lane storm sewer system caused flooding on Timber Lane and Cameron Street during a storm in June of 2021. Watercourse 55 ▪ A culvert crossing deficiency at the culvert crossing Christie Beach Road immediately north of Highway 26 causes flow to spill to the north along the east side of Christie Beach Road resulting in flooding of private property. Watercourse 56 Boulder Channel ▪ Culvert crossing deficiencies at West Ridge Drive and the 9th hole of the Lora Bay Golf course cause flow to spill from Boulder Channel (Watercourse 56) across the golf course and private property and along West Ridge Drive. 2.2.3 Thornbury and Clarksburg Settlement Area ▪ Some drainage infrastructure currently in place in Thornbury is at or approaching the end of its service life and requires replacement. ▪ A lack of an overland flow route along King Street East results in water ponding to significant depths and flooding of private property during major storm events. ▪ The Marsh Street storm sewer discharges to an undocumented drainage system that appears to be the remnants of a flume from an historic mill in Clarksburg. The condition, size, and capacity of portions of this system are unknown. ▪ Other site specific issues within Thornbury west of the Beaver River were identified through the previously completed Thornbury West Drainage Master Plan project. Watercourse 52 ▪ Culvert crossing deficiencies at Highway 26, Grey Road 2, and Clark Street result in flooding of a significant portion of Grey Road 2 and Clark Street. Indian Brook (Watercourse 51) ▪ Under all modeled design storms Indian Brook spills north towards Watercourse 41 between Grey Road 2 and Highway 26 and overwhelms the capacity of Watercourse 41. ▪ Under all modeled design storms there is significant flooding of private property adjacent to Indian Brook between Grey Road 2 and Highway 26 that has the potential to damage property and causes public safety concerns. ▪ A bridge capacity deficiency at Grey Road 2 causes flow to spill north along Grey Road 2 towards Clark Street. Bridge capacity deficiencies at the Georgian Trail and Highway 26 exacerbate the spill towards Watercourse 41 and result in significant flooding of the Georgian Trail and Highway 26. 2.2.4 Camperdown Settlement Area Watercourse 34 ▪ A culvert crossing deficiency at Indian Circle results in water overtopping the road at significant depths and causing public safety concerns. ▪ A lack of outlet channel capacity results in significant flooding of private property that has the potential to damage property north of Highway 26 and causes public safety concerns. Watercourse 32 ▪ A lack of outlet channel capacity results in significant flooding of private property that has the potential to damage property and causes public safety concerns. Watercourse 31 ▪ A culvert crossing deficiency at Hoover Lane results in flooding of the road and flooding of private property that has the potential to damage property and causes public safety concerns. 2.2.5 Craigleith Settlement Area Watercourse 19 ▪ A culvert crossing deficiency at Arrowhead Road causes flow to spill northwest across private property with the potential to damage property. ▪ A culvert crossing deficiency at Highway 26 results in flooding of private property upstream that has the potential to damage property. Watercourse 15 ▪ A lack of channel capacity between the Georgian Trail and Highway 26 results in flooding of adjacent private property with the potential to damage property. Watercourse 10 ▪ A culvert crossing deficiency at Grey Road 19 causes flow to spill towards the north along Grey Road 19 with the potential to overwhelm the downstream system and cause damage to property. ▪ A lack of culvert capacity at Lakeshore Road E causes flow to spill east towards Watercourse 9 and contribute to flooding issues in Watercourse 9. ▪ The watercourse 10 outlet culvert is beneath a private driveway with no municipal easement which restricts the Town’s ability to access and maintain the culvert. Watercourse 9 ▪ A culvert crossing deficiency on Watercourse 9 at Lakeshore Road E, the Georgian Trail and Highway 26 results in water spilling between Watercourse 9 & Watercourse 10 and Watercourse 9 and Watercourse 8. Watercourse 7 ▪ A lack of channel capacity upstream of Lakeshore Road E results in flow spilling from Watercourse 7 to Watercourse 6 upstream of the Georgian Trail. ▪ A lack of channel capacity and a lack of space for the Watercourse 7 outlet channel results in significant flows being conveyed very close to private residences with the potential to damage property and causes a public safety concern. Watercourse 6 ▪ Flow from Watercourse 6 spills over the Georgian Trail and has the potential to flood private properties along Timmins Street. ▪ A culvert crossing deficiency at Highway 26 results in flooding of Highway 26 and Timmins Street and significant flooding of private property that has the potential to damage property and causes a public safety concern. ▪ A lack of channel capacity downstream of Highway 26 results in flooding of Fraser Crescent and Blue Mountain Drive and significant flooding of private property that has the potential to damage property and is a public safety concern. This issue is exacerbated by high water levels in Georgian Bay. 2.2.6 Blue Mountain Village Area Watercourse 7 ▪ A lack of channel capacity between Grey Road 19 and Helen Street results in flooding of properties that has the potential to damage property. Watercourse 1 ▪ A culvert crossing deficiency at Grand Cypress Lane causes significant flooding of Grand Cypress Lane and private property with the potential to damage property and is a public safety concern. ▪ A lack of channel capacity causes flow to spill form Watercourse 1 towards Monterra Road and ultimately into Watercourse 6 contributing to downstream flooding issues. The spill results in flooding of Monterra Road, has the potential to damage property and is a public safety concern. Silver Creek (Watercourse 50) ▪ Due to culvert crossing deficiencies, flow from Silver Creek spills north along Grey Road 19 towards the intersection of Grey Road 19 and Mountain Road resulting in flooding of the intersection and significant flooding of private property that has the potential t o damage property. 2.3 OPPORTUNITY STATEMENT The Town is planning to mitigate drainage deficiencies and replace aging and deteriorating storm infrastructure throughout the study area as part of future works. Opportunity exists to improve the drainage system level of service to a level that conforms with current drainage policies and design guidelines, improves water quality and water balance conditions, reduces flooding and erosion, improves maintenance opportunities and eliminates public safety hazards. As such, the Town has initiated this Master Drainage Plan to identify and evaluate drainage improvements based on their impacts to the physical, natural, social, cultural and economic environments. A set of preferred improvement alternatives having the greatest positive impact and a recommended approach for implementing the alternatives will be the end product of the study. 3 Project Environment This section provides a description of the existing physical, natural, social, cultural and economic environments within the study area. The detailed description of the project environment has been developed from a review of the available background information as well as recent field investigations. 3.1 PHYSICAL ENVIRONMENT 3.1.1 Private Property Within the study area there is a mix of residential, commercial, institutional, industrial, resort/recreational, and open space land uses. The existing land uses across the study area are illustrated on Figures 3A-3C – Existing Land Use Plan enclosed for reference. As discussed, the existing drainage systems are located on both municipal and private property in the study area. Also, there is potential for flooding of private land during minor and major events due to undersized drainage infrastructure and the routing of municipal drainage thro ugh private property. The improvement alternatives proposed aim to prevent/reduce flooding and conveyance of municipal drainage across private property. However, the evaluation of the improvement options will also consider the purchase of these properties or acquiring interest therein (easements) to eliminate flooding of private property. The private properties identified within the existing flood inundation extents are presented in Appendix B and summarized in Table 2. Table 2: Summary of Private Properties within the Flood Inundation Extents SETTLEMENT AREA NUMBER OF PROPERTIES ESTIMATED VALUE Lora Bay 9 $7,982,000 Thornbury and Clarksburg 29 $41,821,000 Camperdown 27 $70,603,000 Craigleith 166 $202,875,400 Blue Mountain Village 51 $72,503,600 Total 282 $395,785,000 Note: Estimated Value = Grey County Maps Assessed Value x 2.6 (ratio of average assessed value to recent average sale price) 3.1.2 Storm Sewer Within the study area, the drainage systems consist of storm sewers, culverts, ditches, and open channels. The existing drainage infrastructure is illustrated on Drawings included in the Existing Conditions Report enclosed in Appendix A for reference. As per Town guidelines, the minor drainage system (storm sewer) shall be designed to convey the 1:5-year (minimum) design storm peak flow. Watercourses and channels shall be capable of conveying the Regulatory storm peak flow without flooding adjacent private property. Flooding of existing buildings and/or property shall be eliminated where feasible. Road culvert crossings and road elevations shall be designed to satisfy the design flood frequency criteria for the corresponding road classification. In the Study Area, the roads are classified as arterial, collector, and local roads. The design flood frequency criteria for each road classification is provided in Table 1 in section 1.5.1. Some of the existing storm infrastructure in the Town is reaching its service life expectancy and deteriorating. A majority of the aging storm sewers are undersized considering historic rainfall data and current climate models predict future increases in rainfall intensities and volumes. In some locations, municipal storm infrastructure is located on private property outside the municipal right-of-way making it difficult to access and maintain. Frequent nuisance flooding during minor storm events, potential public safety hazards, and access/maintenance issues are common throughout the study area. For these reasons, the replacement of storm infrastructure throughout much of the Town is required. The extent/locations of the existing minor and major drainage system deficiencies are described further in Sections 4 and 5 of this report. For more details refer to the Drainage Master Plan Existing Conditions Report enclosed in Appendix A. It is recommended that consideration be given to upsizing the local storm sewers to satisfy current design standards as part of future road reconstru ction projects. Similarly, relocating storm sewer to the municipal road allowance should also be considered. Also, it is recommended that consideration be given to service the streets absent of a minor drainage system throughout the study area. 3.1.3 Existing Infrastructure (Sanitary, Water and Utilities) Utilities including sanitary sewers, water main, gas, hydro and other overhead and buried utilities have been identified in the study area from the available record drawings. Conflicts with existing utilities will be reviewed for each improvement alternative proposed and potential conflicts and resolutions will be identified. Minor utility relocations and lowering of existing sanitary sewer and water main may be required to accommodate the improvement alternatives being evaluated. 3.1.4 Transportation System In the Study Area, the roads are classified as arterial, collector, and local roads. The road classifications are illustrated on the Town of The Blue Mountains Official Plan Schedule ‘B-1’ and ‘B-2’ Transportation Plans overleaf. The Town is currently undertaking a Transportation Master Plan which will identify short, medium, and long-term actions, strategies, or policies for the Town to achieve the TMP objectives. 3.1.5 Floodplain The floodplain along the watercourses throughout the Town was originally developed by the GSCA. Existing flooding is an important consideration for this study. The flooding has caused historic damage to both private and municipal property and causes conce rn for public safety. It is recommended the Town progressively acquire land or easements for drains, watercourses and storage areas crossing or upon private lands, where it is considered to be in the Town’s interest to do so. This includes lands located in the floodplain. The delineation of the existing floodplain through the study area is further described in the Drainage Master Plan Existing Conditions Report enclosed in Appendix A. As discussed, the private properties identified within the existing floodplain are presented in Appendix B. It is noted that the floodplain delineated through this DMP has not been adopted as the Regulatory Floodplain by the local Grey Sauble Conservation Authority or the Nottawasaga Valley Conservation Authority and should not be used as such. 3.1.6 Water Quality The study area is predominantly developed. A significant portion of the developed areas do not have water quality controls that meet current standards, but this is not considered as potential new sources of water quality degradation. Based on the substandard existing condition, opportunities to improve water quality should be considered where feasible, including the following: 1. Low Impact Development measures; 2. SWMF’s; and 3. Mechanical Devices. All new developments shall provide the minimum Enhanced Level water quality control as specified in the Stormwater Management Planning and Design Manual unless it can be demonstrated to the satisfaction of the Director (MECP) that it is impractical to achieve this level of protection. Lot 41 Lot 40 Lot 39 Lot 37 Lot 36 Lot 35 Lot 34 Lot 33 Lot 32 Lot 31 Lot 30 Lot 29 Lot 28 Lot 27 Lot 26 Lot 25 Lot 24 Lot 23 Lot 22 Lot 21 Lot 20 Lot 19 Lot 18 Lot 17 Lot 16 Lot 15 Lot 14 Lot 13 Lot 12 Lot 11 Lot 10 Lot 9 Lot 8 Lot 7 Lot 6 Lot 5 Lot 4 Lot 3 Lot 2 Lot 1 XII XI X IX VIII VII VI V IV III II I Highwa y 2 6 Arthu r S t W Highwa y 2 6 Gre y R o a d 2 Grey Road 119 Grey Road 19 Grey Road 40 Gre y R o a d 1 3 Gre y R o a d 2 1 Mar s h S t Alfre d S t W Sce n i c C a v e s R o a d Matilda St Gre y R o a d 1 1 3 Clark St Monterra Rd Chr i s t i e B e a c h R d 39th Sideroad Arro w h e a d R d Craigleith Rd Sleepy Hollow Rd Lor a B a y D r 10th L i n e 4th L i n e 6th L i n e 21st Sideroad 6th Sideroad 7th L i n e 12th Sideroad 18th Sideroad Pretty River Rd 3rd L i n e 9th Sideroad 11th L i n e 24th Sideroad 30th Sideroad 33rd Sideroad Suns e t B l v d 5th L i n e Cameron S t The B l u e M o u n t a i n s - M e a f o r d T o w n l i n e 2nd L i n e Lake D r Lakesho r e R d E Lon g P o i n t R d Clark St Osprey-The Blue Mount a i n s T o w n l i n e Main St The B l u e M o u n t a i n s - C l e a r v i e w T o w n l i n e Peel St N Old Lakeshore Rd High B l u f f L a n e Cam p e r d o w n R d 3rd Sideroad Hidden Lake Rd War d s R d Maple Lane Poplar Sideroad Bro p h y ' s L a n e Teskey D r Mis s i o n R d Scandia Lane Arth u r T a y l o r L a n e Cla i r e G l e n Mar t i n G r o v e Hoover La n e Gibson Way Hap p y V a l l e y R d 12th Sideroad 12th Sideroad 3rd Sideroad 6th L i n e 12th Sideroad 3rd L i n e 10th L i n e 6th L i n e 11th L i n e 5th L i n e Osprey-The Blue Mountai n s T o w n l i n e 6th Sideroad 12th Sideroad 18th Sideroad Osprey-The Blue Mounta i n s T o w n l i n e 3rd L i n e 9th Sideroad 6th Sideroad Gre y R o a d 2 Gre y R o a d 2 Gre y R o a d 2 .0 1 2 3 4 5 kilometers Gibraltar Ravenna Heathcote The Blue MountainsOfficial Plan Schedule 'B-1'Transportation See Schedule 'B-2' Temporary Local Road Designations Community Gateway Highway 26 County Roads Minor Collector Roads Bruce Trail - Existing Route Georgian Trail Trails Major Collector Roads Local Roads Local Heritage Roads Private Roads Proposed Local Roads Proposed Collector Roads June 2016Download PDF: www.thebluemountains.ca Note: This Schedule forms part of the Official Plan and must be read and interpreted in conjunction with the text. The information depicted on this Schedule has been compiled from various sources.While every effort has been made to accurately depict the information, data/mapping errors may exist. Lot 35 Lot 34 Lot 33 Lot 32 Lot 31 Lot 30 Lot 29 Lot 28 X IX VIII Highwa y 2 6 Arthu r S t W King S t E Bridge St E High w a y 2 6 Grey Road 40 Gre y R o a d 2 Mar s h S t Alfre d S t W Bruc e S t S Gre y R o a d 1 3 Matilda St Gre y R o a d 1 1 3 Clark St 10th L i n e Alice S t W Bay S t E Cameron S t Victo r i a S t S Dunc a n S t W Napi e r S t W King S t W Clark St Peel St S John St Lake Dr Hill S t Huro n S t W Peel St N High B l u f f L a n e Edward St Elma S t S Bay v i e w A v e Mill S t Russell St W Alber t S t Elgin S t S Russell St E Lake S h o r e R d Mar y S t Loui s a S t W Beaver St S Barin g S t Fulton St 33rd Sideroad Lake s h o r e D r Napi e r S t E 30th Sideroad Brook St Pyatt A v e Lans d o w n e S t N Alice S t E Grey S t N Har b o u r S t Cotta g e A v e Huro n S t E Rive r s i d e C r e s 10th L i n e 10th L i n e The Blue MountainsOfficial Plan Schedule 'B-2'TransportationThornbury and Clarksburg June 2016 Note: This Schedule forms part of the Official Plan and must be read and interpreted in conjunction with the text. The information depicted on this Schedule has been compiled from various sources. While every effort has been made to accurately depict the information, data/mapping errors may exist. Download PDF: www.thebluemountains.ca Designations Highway 26 Community Gateway Trails County Roads Major Collector Roads Minor Collector Roads Local Heritage Roads Local Roads Private Roads Georgian Trail Bruce Trail - Existing Route Proposed Collector Roads Proposed Local Roads .0 250 500 750 1,000 Metres 3.1.7 Erosion A Fluvial Geomorphologic & Erosion Threshold Assessment was completed by Water’s Edge to identify the areas of active erosion and determine erosion thresholds to aid in the development and evaluation of the alternative drainage solutions. The assessment highlights the active erosion sites on each watercourse and provides recommendations for mitigation. Erosion is an important consideration for this study. The Fluvial Geomorphologic & Erosion Threshold Assessment is included in Appendix C for reference. 3.1.8 Source Water Protection The Saugeen, Grey Sauble, Northern Bruce Peninsula Source Protection Plan and the South Georgian Bay Lake Simcoe Source Protection Plan have been developed to protect existing and future drinking water sources from significant drinking water threats. A number of potential significant drinking water threats have been identified in the Source Protection Plans. The Town uses Georgian Bay for its potable drinking water supply. The applications of pesticides, fertilizers and road salts are significant drinking water threats that impact stormwater runoff and can be transferred via drainage systems and watercourses to Georgian Bay. 3.1.9 Parkland The existing parks are an important consideration within the study area. The parks provide a green space amenity within the Town for pedestrian connectivity and community use. The parks are features enjoyed by not only surrounding residents but residents throughout the Town. Parkland has been identified for its potential inclusion of low impact development me asures and/or stormwater management facilities. Low impact development measures can be constructed in existing parklands to reduce minor drainage system peak flows, enhance water quality treatment, improve the water balance and reduce erosion all while ma intaining the existing function/use of the parkland. SWMF’s may provide the added benefit of reducing major drainage system peak flows, however at a cost of disturbing the surface features, function and use of the parkland or a portion of it. 3.2 NATURAL ENVIRONMENT As part of the development of the background studies, the natural heritage features throughout the Town have been mapped. The natural heritage features are illustrated on Figures included in the Natural Heritage Assessment prepared by Birks Natural Heritage (September 2022) enclosed in Appendix D. Birks Natural Heritage Consultants (Birks) completed an existing natural heritage features evaluation in the summer of 2022 in support of this Drainage Master Plan. The evaluation involved general surveys of habitat types, Significant Wildlife Habitat (SWH) for Ecoregion 6E, fish and fish habitat, and habitat for threatened and endangered species. The results of the evaluation are summarized in the following sections and detailed in the Natural Heritage Assessment enclosed. 3.2.1 Blue Mountains Slopes and Delphi Point ANSI The Blue Mountain Slopes and Delphi Point Areas of Natural and Scientific Interest (ANSI) are located within the study area. 3.2.2 Wetlands Components of the Silver Creek Provincially Significant Wetland (PSW) Complex are mapped within the study area and background mapping indicates the presence of unevaluated wetlands within the study area. 3.2.3 Significant Woodland The County of Grey provides Significant Woodlands mappin g which was developed with assistance from the Ministry of Northern Development, Mining, Natural Resources and Forestry (MNDMNRF). Significant woodlands are present within the study area. 3.2.4 Significant Valleylands Significant Valleylands were identified by the GSCA throughout Grey County and within the study area and include 200 m wide corridors. The county recommends that detailed delineations of Significant Valleylands be evaluated of a site-specific basis through an EIS. 3.2.5 Significant Wildlife Habitat No species-specific surveys were conducted as part of this study. However, review of the Significant Wildlife Habitat Criteria Schedules for Ecoregion 6E determined the following Significant Wildlife Habitat functions potentially occurring within the study area: ▪ Seasonal Concentration Areas of Animals ▪ Colonial Nesting Bird Breeding Habitat (Banks and Cliffs, Trees/Shrubs, and Ground) ▪ Raptor Wintering Area ▪ Bat Maternity Colonies ▪ Turtle Wintering Areas ▪ Reptile Hibernaculum ▪ Specialized Habitat for Wildlife ▪ Turtle Nesting area ▪ Seeps and Springs ▪ Amphibian Breeding Habitat (Woodland and Wetland) ▪ Woodland Area-Sensitive Bird Breeding Habitat ▪ Marsh Breeding Bird Habitat ▪ Shrub/Early Successional Bird Breeding Habitat ▪ Terrestrial Crayfish ▪ Special Concern and Rare Wildlife Species – Hart’s-tongue Fern, Snapping Turtle, Eastern Wood-pewee, Wood Thrush, Bald Eagle, Canada Warbler, Common Nighthawk, Silver Lamprey (as per O. Reg. 230/08 made under the ESA, currency date of January 26, 2022) 3.2.6 Fish and Fish Habitat In addition to the five (5) main watersheds which outlet to Georgian Bay within the study area, there are numerous smaller watersheds and drainage features which originate at the Niagara Escarpment and drain north to Georgian Bay. Fish species documented within the study area include: Blacknose Dace, Bluntnose Minnow, Brook Stickleback, Brown Trout, Central Mudminnow, Common Shiner, Creek Chub, Emerald Shiner, Fathead Minnow, Hornyhead Chub, Johnny Darter, Longnose Dace, Longnose Sucker, Northern Redbelly Dace, Rainbow Smelt, Rainbow Trout, Rock Bass, Rosyface Shiner, Sand Shiner, Sculpins and White Sucker. 3.2.7 Habitat of Threatened and Endangered Species No species-specific surveys were conducted as part of this assessment. However, the habita t requirements of those species listed as Threatened and Endangered under the Endangered Species Act were considered in relation to the habitat features noted within the study area. It was determined that potential habitat for several Threatened and Endangered species is present in the study area and a summary of Species at Risk that may occur within the various habitat types is included in the Natural Heritage Assessment enclosed in Appendix D for reference. 3.3 SOCIAL ENVIRONMENT 3.3.1 Property Value Existing flooding and the presence of municipal infrastructure on private property can negatively impact property values and the Town’s ability to improve existing drainage infrastructure. As such, any improvement alternative that will prevent/reduce flooding on private property and relocate municipal infrastructure into municipally owned lands would be a positive improvement. The assessed and estimated property values of the private properties identified within the floodplain are summarized in Table 2 and provided in Appendix B. 3.3.2 Public Safety The existing drainage systems throughout the study area operate at levels below current Town design standards resulting in flooding on municipal and private property. The flooding presents a potential for public safety concerns. The conveyance of both minor and major storm flows and compliance with the Provincial Policy Statement in this regard is an important consideration in the review of improvement alternatives. In addition to flooding, the lack of safety grates on storm sewers and culvert inlets/outlets, lack of signage around SWMF’s describing the potential hazards, and the lack of pedestrian barricades at fall hazards pose a threat to public safety. As such, the installation of safety grates, signage and pedestrian barricades is highly recommended. 3.4 CULTURAL/ARCHAEOLOGICAL ENVIRONMENT Archeoworks Inc. completed a Stage 1 Archeological Assessment in the summer of 2021 in support of this Drainage Master Plan. Based on the background research and a general property inspection, elevated and uncertain levels of land-based archaeological potential as well as areas of elevated marine-based archaeological potential were established within the study area. The assessment concluded that the only areas that can definitively be eliminated from requiring further assessment within the study area are those properties for which a Stage 1 background study, Stage 2 property assessment, Stage 3 site-specific assessment, and/or Stage 4 mitigation of development impacts has previously been carried out wherein the report recommended the property being cleared of requiring further archaeological assessment or for which an archaeological site was discovered and determined to be of no further cultural heritage value or interest. The historical limits of the Town of Thornbury and the Village of Clarksburg retain elevated potential for deeply buried archeological resources. Several previously registered archeological sites with further cultural heritage value or interest and two cemeteries requ iring special consideration are located within the study area. Any construction activities which impact any of the above identified areas will require further land-based archeological assessment or a marine investigation undertaken by a licenced marine archaeologist, as appropriate. It is noted that no construction activities shall take place within the study area prior to the Ministry of Heritage, Sport, Tourism and Culture Industries confirming in writing that all archaeological licensing and technical review requirements have been satisfied. The conclusions and recommendations of the archeological assessment are detailed in the Stage 1 Archeological Assessment for The Town of The Blue Mountains Drainage Master Plan enclosed in Appendix E for reference. 3.5 ECONOMIC ENVIRONMENT 3.5.1 Drainage System Maintenance Costs Throughout the study area, the Town incurs costs to maintain their existing drainage systems on both municipal and private property. Clearing obstructions, repairing erosion and removing accumulated sediment are routine maintenance activities the Town coordinates to complete. Unfortunately, as existing storm infrastructure reaches its service life expectancy and deteriorates, the maintenance costs increase. Limited access for Town Operations staff to drainage infrastructure on both private and municipal lands also increases maintenance costs and risk of failure. The improvement alternatives being considered aim to attenuate peak flows, improve water quality, increase conveyance capacities and prevent/reduce the flooding of private property. As such, the maintenance costs throughout the Town is expected to be reduced. However, annual periodic maintenance will be required to maintain the function of stormwater management facilities (SWMF) and Low Impact Development (LID) measures. Improvement alternatives proposing SWMFs or LID measures will require routine maintenance. 3.5.2 Property Acquisition Costs It is recommended that the Town acquire lands or interests therein (easements) adjacent to the watercourse where it is in the Town’s interest to do so. Future development lands may be dedicated to the Town through the Subdivision Agreement or Site Plan Conditions. Existing properties, or portions of the properties, may be acquired through negotiations with the landowner or under the worst case scenario through expropriation. Currently, extensive flooding of private property occurs throughout the study area during major storm events. The private properties identified within the existing floodplain are presented in Appendix B and summarized in Table 2. The improvement alternatives proposed aim to prevent/reduce flooding of private property. However, to implement several of the improvement alternatives, acquisition of private property by the Town is required. The cost to acquire these lands will be included in project cost estimates prepared for each alternative. 3.5.3 Construction Costs Each improvement alternative has a capital cost to construct. Project cost estimates will be prepared for each improvement alternative considered to aid in the evaluation of the economic impacts to implement each alternative. Consideration will be given to implementing the alternative improvement options as part of future renewal projects to reduce costs. For those projects recommended to occur as part of future renewal projects, the cost to construct the improvement will be compared against the cost to replace existing infrastructure. 4 Existing Conditions System Analysis As previously discussed, an Existing Conditions Report was prepared for the study area which included development of minor and major drainage system models to be used for the identification and analysis of minor and major drainage system deficiencies. A PCSWMM hydrologic/hydraulic model of the minor drainage systems throughout the study area and a Visual OTTHYMO hydrologic model and HEC-RAS hydraulic model of the major drainage systems were prepared. The models for the Existing Conditions Report were developed from information provided by the Town including GIS shapefiles of the minor drainage SWM infrastructure, record/design drawings of the existing SWM infrastructure, and additional information collected by Tatham through field visits and topographic survey. The results of the models represent existing conditions across the study area and are summarized in the following sections. The minor and major drainage systems, the hydraulic and hydrologic analysis and the minor and major system deficiencies are fully detailed in the Existing Conditions Report included in Appendix A. 4.1 EXISTING DRAINAGE SYSTEMS The minor drainage systems are defined as networks of storm sewer, ditches and culverts collecting and conveying surface runoff from private and municipal lands to significant watercourses and Georgian Bay during frequent (minor) storm events. The major drainage systems are defined as municipal roadways, overland flow routes, drainage channels and significant watercourses conveying surface runoff during infrequent (major) storm events. The development of the minor and major drainage system models is describ ed in the Existing Conditions Report included in Appendix A. 4.2 MINOR DRAINAGE SYSTEM ANALYSIS As previously discussed, PCSWMM was selected as the software to model the minor drainage system hydrology and hydraulics. For more details regarding the development of the minor drainage system PCSWMM model, refer to the Existing Conditions Report enclosed in Appendix A for reference. The 1:5-year return frequency design storm peak flow results of the existing conditions minor drainage system model are summarized in Table 3 for the governing rainfall distribution for each watershed. Detailed PCSWMM model results are included with the Existing Conditions Report enclosed in Appendix A for reference. Table 3: Existing Conditions Minor Drainage System Model Peak Flow Summary WATERCOURSE / OUTLET AREA (ha) GOVERNING RAINFALL DISTRIBUTION 1:5-YEAR PEAK FLOW (m3/s) Watercourse 1 332.9 MTO (2010) SCS 24hr 3.1 Watercourse 2 32.8 MTO (2010) SCS 24hr 0.3 Watercourse 6 614.51 MTO (2010) SCS 24hr 6.4 Watercourse 7 150.2 MTO (2010) SCS 24hr 4.4 Outlet 8 19.6 MTO (2010) Chicago 3hr 0.2 Watercourse 9 191.8 MTO (2010) SCS 24hr 4.0 Watercourse 10 67.6 MTO (2010) SCS 24hr 2.9 Outlet 13 84.9 MTO (2010) SCS 24hr 4.9 Watercourse 14 93.0 MTO (2010) SCS 24hr 3.7 Outlet 45 31.5 MTO (2010) SCS 24hr 1.2 Watercourse 15 80.0 MTO (2010) SCS 24hr 4.6 Watercourse 18 24.4 MTO (2010) SCS 24hr 0.3 Watercourse 19 341.1 MTO (2010) SCS 24hr 14.5 Watercourse 21 112.2 MTO (2010) SCS 24hr 3.5 Watercourse 22 60.8 MTO (2010) SCS 24hr 0.5 Watercourse 25 57.5 MTO (2010) SCS 24hr 1.3 Watercourse 26 113.7 MTO (2010) SCS 24hr 4.7 Watercourse 28 55.9 TOBM (2009) Chicago 3hr 0.9 Watercourse 29 23.6 MTO (2010) SCS 24hr 0.9 Outlet 30 34.8 MTO (2010) SCS 24hr 0.9 Watercourse 31 129.5 MTO (2010) SCS 24hr 5.4 WATERCOURSE / OUTLET AREA (ha) GOVERNING RAINFALL DISTRIBUTION 1:5-YEAR PEAK FLOW (m3/s) Watercourse 32 352.6 MTO (2010) SCS 24hr 9.7 Outlet 33 60.5 TOBM (2009) Chicago 3hr 0.9 Watercourse 34 575.5 MTO (2010) SCS 24hr 11.3 Watercourse 40 115.3 MTO (2010) SCS 24hr 0.4 Watercourse 42 29.0 MTO (2010) SCS 24hr 0.7 Silver Creek North of Holly Court (50) 29.2 MTO (2010) SCS 24hr 0.2 Silver Creek South of Holly Court (50) 199.0 MTO (2010) SCS 24hr 5.0 Silver Creek South of Mount View Court (50) 1412.3 MTO (2010) SCS 24hr 32.5 Indian Brook (51) 3,544.8 MTO (2010) SCS 24hr 52.0 Watercourse 52 310.0 MTO (2010) SCS 24hr 0.9 Little Beaver River (54) 1,559.8 MTO (2010) SCS 24hr 16.1 Watercourse 55 160.3 MTO (2010) SCS 24hr 3.0 Boulder Creek (56) 324.6 MTO (2010) SCS 24hr 3.0 Arthur St. W 14.9 MTO (2010) Chicago 3hr 0.9 Cameron St. 26.1 MTO (2010) Chicago 3hr 1.9 Elgin St. 13.9 MTO (2010) Chicago 3hr 1.1 Louisa St. E 14.6 MTO (2010) SCS 24hr 0.8 Mary St. 55.2 MTO (2010) SCS 24hr 1.0 Minor Outlets2 169.6 Varies Varies 1. Does not include spill into Watercourse 6. 2. Minor outlets are those with no significant infrastructure analyzed. 4.3 MAJOR DRAINAGE SYSTEM ANALYSIS The major drainage system hydrology was modeled using Visual OTTHYMO (VO) software and the major drainage system hydraulics were modeled using HEC-RAS software. To establish the return frequency design storm peak flows for the Beaver River, historical flow records from the Environment Canada gauge (Station 02FB009) located at Slabtown were analyzed using a Bulletin 17B Flood Frequency Analysis. A 2D HEC-RAS hydraulic model was developed to analyze the area encompassing the downstream reaches of Watercourse 1 to Watercourse 10 where significant flow spills between watercourses. For more details regarding the development of the major drainage system hydrologic and hydraulic models, refer to the Existing Conditions Report enclosed in Appendix A for reference. The Regional (Timmins) Storm peak flow and the peak flows for the 1:5-year, 1:25-year and 1:100- year return frequency design storms are summarized in Table 4 for each watercourse/outlet to Georgian Bay. Table 4: Existing Conditions Major Drainage System Model Peak Flow Summary WATERCOURSE / OUTLET AREA (ha) DESIGN STORM PEAK FLOW (m3/s) 1:5-YEAR 1:25-YEAR 1:100-YEAR TIMMINS Watercourse 1 Upstream of Spill 239.4 8.4 15.4 21.2 19.5 Downstream of Spill 63.7 0.5 0.9 1.3 2.3 Watercourse 2 32.8 0.3 0.6 0.8 1.2 Watercourse 6 Upstream of Spill 504.8 11.2 18.6 25.8 30.0 Downstream of Spill 100.0 0.7 1.2 1.6 2.8 Watercourse 7 Upstream of Spill 143.0 6.7 11.6 15.5 12.3 Downstream of Spill 16.9 0.4 0.7 0.9 1.0 Outlet 8 19.6 0.5 0.9 1.2 1.3 Watercourse 9 191.8 5.9 10.0 13.6 14.0 Watercourse 10 67.6 4.4 7.6 10.2 6.3 WATERCOURSE / OUTLET AREA (ha) DESIGN STORM PEAK FLOW (m3/s) 1:5-YEAR 1:25-YEAR 1:100-YEAR TIMMINS Outlet 13 81.7 5.9 9.8 13.4 7.6 Watercourse 14 93.0 3.8 6.5 8.8 7.8 Outlet 45 31.5 1.7 2.9 4.0 2.5 Watercourse 15 80.0 4.2 7.1 10.1 7.3 Watercourse 18 24.4 0.9 1.5 2.1 1.8 Watercourse 19 341.1 14.3 26.3 37.6 29.0 Watercourse 21 112.2 4.9 8.3 11.5 9.3 Watercourse 22 60.8 1.3 2.4 3.4 3.6 Outlet 23 15.1 0.4 0.7 1.0 1.0 Outlet 24 21.6 0.5 1.0 1.4 1.4 Outlet 25 56.6 2.8 4.8 6.6 5.1 Outlet 26 113.7 4.4 7.2 9.8 9.0 Watercourse 28 56.2 3.3 5.7 7.7 4.9 Watercourse 29 23.4 0.9 1.7 2.4 1.7 Outlet 30 34.8 1.6 3.0 4.1 2.8 Watercourse 31 129.5 6.4 10.8 14.9 11.2 Watercourse 32 352.6 11.9 20.1 27.5 27.2 Outlet 33 60.5 2.4 4.4 6.1 4.3 Watercourse 34 575.5 19.5 33.7 44.3 41.6 Watercourse 40 115.3 1.6 2.9 4.1 5.1 Watercourse 41 14.6 0.6 0.9 1.2 0.8 Watercourse 42 29.0 0.8 1.2 1.7 1.4 WATERCOURSE / OUTLET AREA (ha) DESIGN STORM PEAK FLOW (m3/s) 1:5-YEAR 1:25-YEAR 1:100-YEAR TIMMINS Silver Creek North of Holly Court (50) 42.5 0.5 1.1 1.7 2.3 Silver Creek South of Holly Court (50) 240.9 9.6 15.2 19.4 17.1 Silver Creek South of Mount View Court (50) 1,412.3 30.0 53.6 75.6 78.4 Indian Brook (51) 3,544.5 82.3 141.6 194.1 223.8 Watercourse 52 310.0 2.8 5.4 7.8 12.1 Little Beaver River (54) 1,562.6 37.3 64.9 89.0 98.5 Watercourse 55 160.3 7.0 11.8 16.1 13.9 Boulder Channel (56) 311.1 3.7 10.0 14.8 19.1 The peak flow results from the VO hydrologic analysis of the 1:2-year through 1:100-year return frequency design storms and the Regional Storm were entered into the HEC-RAS 1D steady state hydraulic model at flow change locations specified at each bridge/culvert crossing. There is significant spill and redistribution of flow between Watercourse 1, 2, 6, 7, 9, 10 and Outlets 8, 11 and 12. This has been analyzed through a 2D HEC-RAS unsteady state model that also accounts for storage in the watershed (floodplain and watercourse). Peak inflows, spills and ultimate outflows are summarized in Table 5. For more details regarding the spills and distribution of flows in the 2D model area, refer to the Existing Conditions Report. Table 5: Existing Conditions Total Flow Reduction/Redistribution Summary LOCATION DESIGN STORM PEAK FLOW (m3/s) 1:5-YEAR 1:25-YEAR 1:100-YEAR TIMMINS Watercourse 1 Total Inflow 8.87 15.91 22.02 21.79 Watercourse 1 Total Outflow 1.72 1.83 2.08 2.32 Watercourse 2 Inflow at Highway 26 0.10 0.18 0.26 0.35 Total Flow Across Highway 26 (Including Spill) 0.10 0.18 0.58 2.11 Watercourse 6 Total Inflow 12.65 21.23 28.31 34.08 Watercourse 6 Total Outflow 10.95 15.41 21.58 38.54 Watercourse 7 Total Inflow 6.16 11.03 15.11 12.00 Watercourse 7 Total Outflow 1.86 2.54 3.43 3.00 Outlet 8 Total Inflow 0.48 0.85 1.19 1.27 Outlet 8 Total Outflow 3.07 7.17 10.69 10.06 Watercourse 9 Total Inflow 5.88 9.99 13.61 14.01 Watercourse 9 Total Outflow 3.36 5.69 6.27 6.25 Watercourse 10 Total Inflow 4.25 6.59 8.57 6.29 Watercourse 10 Total Outflow 3.90 5.85 6.58 6.35 Outlet 11 Total Inflow 0.12 0.20 0.37 0.22 Outlet 11 Total Outflow 0.24 0.70 1.07 0.97 Outlet 12 Total Inflow 0.39 0.63 0.93 0.55 Outlet 12 Total Outflow 0.00 0.00 0.00 0.00 Total Inflow 38.90 66.61 90.37 90.56 Total Outflow 25.20 39.37 52.28 69.60 It is noted that the 2D unsteady state analysis accounts for the storage component within the analysis area. As water levels rise, the utilization of storage volume within the system also increases. The amount of storage upstream of the ultimate outlet accounts for the significant reduction in peak flow presented in Table 5. The most notable storage area is the Monterra wetland south of the Georgian Trail. 4.4 DRAINAGE SYSTEM DEFICIENCY IDENTIFICATION The existing drainage deficiencies were established according to the Town’s Engineering Standards. The deficiencies identified through the hydrologic/hydraulic analysis are presented on the Minor and Major Drainage System Deficiencies maps (Drawings 1A through 3H) included in the Existing Conditions Report enclosed and are described further in the following sections. Drainage deficiencies that have been reported by the public or observed by Town or Tatham staff are described in Appendix A of the Existing Conditions Report. 4.4.1 Minor Drainage System Deficiencies Minor drainage system design standards deficiencies were established according to the Town’s Engineering standards. The minor drainage system PCSWMM model was used to assess the conveyance capacity of the Town’s storm sewer systems during the 1:5-year return frequency design storms. The worst-case design storm scenario results for each sewer and maintenance hole are used to identify deficiencies. For this assessment, the storm sewer has been characterized as follows: 1. Design Standard Deficiencies – storm sewer does not satisy Town Engineering Standards criteria for minimum sewer size, minimum sewer grade, or minimum/maximum flow velocity. 2. Peak Flow/Storm Sewer Full Flow Capacity (Qmax/Qfullflow) < 85% - storm sewer capacity exceeds design storm peak flow (storm sewer has adequate capacity) by greater than 15% and satisfies the current municipal conveyance criteria. 3. 85% <= Peak Flow/Storm Sewer Full Flow Capacity (Qmax/Qfullflow) < 100% - storm sewer capacity exceeds design storm peak flow (storm sewer has adequate capacity) by less than 15%. As such, the peak flow is approaching full flow capacity. 4. 100% <= Peak Flow/Storm Sewer Full Flow Capacity (Qmax/Qfullflow) < 115% - design storm peak flow exceeds storm sewer capacity (deficient conveyance capacity) by up to 15% - moderate exceedance. 5. Peak Flow/Storm Sewer Full Flow Capacity (Qmax/Qfullflow) >= 115% - design storm peak flow exceeds storm sewer capacity (deficient conveyance capacit y) by greater than 15% - severe exceedance. Similarly, the storm maintenance hole deficiencies have been characterized as follows based on maintenance hole surcharging: 1. Maintenance Hole Surcharging < 0 m – no overland flow. 2. 0 m <= Maintenance Hole Surcharging < 0.1 m - minimal overland flow depth. 3. 0.1 m <= Maintenance Hole Surcharging < 0.3 m - overland flow depth satisfies safe access/egress criteria. 4. Maintenance Hole Surcharging >= 0.3 m - overland flow depth exceeds safe access/egress criteria. The minor drainage system deficiencies are presented on the Existing Condition Storm Sewer Deficiencies Maps (Drawings 1A through 1H and 3A through 3H) included in the Existing Conditions Report enclosed. Summaries of the design standard and existing condition capacity deficiencies within the storm sewer systems in the Study Area are provided in Tables 6 and 7 and complete lists of storm sewer and maintenance hole deficiencies are included in the Existing Conditions Report. Table 6: Existing Conditions Storm Sewer Deficiency Summary WATERCOURSE / OUTLET # STM DESIGN STANDARDS DEFICIENCIES SEWER CAPACITY DEFICIENCIES Q<85% 85%<Q<100 % 100%<Q<115% Q>115% Lora Bay 172 27 110 15 19 28 Thornbury and Clarksburg 353 85 189 40 31 93 Camperdown 139 38 71 18 13 37 Craigleith 187 68 130 18 12 27 Blue Mountain 323 38 178 39 38 68 Total 1174 256 678 130 113 253 Table 7: Existing Conditions Maintenance Hole Surcharge Deficiency Summary WATERCOURSE / OUTLET # MH MH SURCHARGING DEPTH DEFICIENCIES D<0.00m 0.00m<D<0.10 m 0.10m<D<0.30 m D>0.30m Lora Bay 172 152 9 6 5 Thornbury and Clarksburg 346 284 37 21 4 Camperdown 137 126 3 6 2 Craigleith 176 147 11 13 5 Blue Mountain 307 279 3 20 5 Total 1138 988 63 66 21 4.4.2 Major Drainage System Deficiencies For the major drainage systems, road crossing culverts must satisfy the design flood frequency criteria specified in Table 1. Also, overtopping deficiencies were identified based on the following safe access/egress criteria: ▪ Maximum depth of overland flow exceeds 0.30 m; ▪ Maximum velocity of overland flow exceeds 1.7 m3/s; ▪ Maximum depth velocity product of overland flow exceeds 0.40 m2/s. The major drainage system deficiencies and floodpla in mapping are presented on Drawings 2A through 2H and 5A through 5M included in the Existing Conditions Report enclosed. A summary of the bridge/culvert deficiencies is provided in Table 8 and a detailed summary is included in the Existing Conditions Report enclosed. Table 8: Existing Conditions Bridge/Culvert Crossings Deficiency Summary WATERCOURSE/OUTLET # OF CROSSINGS # OF CAPACITY DEFICIENCIES # OF OVERTOPPING DEFICIENCIES # OF DEFICIENT CROSSINGS Lora Bay 20 16 8 17 Thornbury and Clarksburg 43 23 13 24 Camperdown 39 20 9 20 Craigleith 72 49 33 57 Blue Mountain 34 16 7 16 Total 208 124 70 134 4.4.3 Stormwater Management Facility Deficiencies The stormwater management facilities identified throughout the Town were included in the VO and PCSWMM hydrologic/hydraulic models to account for their effect on peak flows. The SWMFs were analyzed from a water quantity and water quality perspective to ass ess the effectiveness of each SWMF in attenuating peak flows and treating stormwater runoff. To assess the existing SWMFs throughout the Town from a water quantity perspective, the VO hydrologic model was used to determine the required active storage volumes for each SWMF to store the 1:100-year peak flow. The required storage volumes were then compared to the actual storage volumes provided by each SWMF. The peak flow reduction provided by each SWMF was determined by comparing the peak flow into the SWMF against the peak outflow from the SWMF. To assess the SWMFs from a water quality perspective the permanent pool, extended detention, and erosion control storage volumes provided by the SWMFs were compared to the guidelines for water quality treatment provided by the MECP Stormwater Management Planning and Design Manual. A summary of the stormwater management facility deficiencies is provided in Tables 9 and 10. For further details of the water quantity and water quality assessments, refer to the Existing Conditions Report. Table 9: Existing Conditions SWMF Water Quantity Assessment Summary WATERCOURSE / OUTLET SWMF ID ACTIVE STORAGE VOLUME (m3) PEAK FLOW REDUCTION Required Provided 1:5-Year Minor Storm 1:100-Year Major Storm Watercourse 1 1402 1,981 2,096 95% 82% 1403 12,195 13,337 99% 92% Watercourse 6 6401 25,212 28,000 57% 71% 6402 1,932 2,095 85% 57% 6403 6,676 6,000 85% 74% 6405 4,487 3,915 87% 88% 6406 9,145 15,800 22% 12% 6408 6,166 2,789 62% 50% 6409 176 193 92% 94% Watercourse 9 9401 2,231 1,672 32% 21% Watercourse 9 9402 5,179 8,539 78% 69% Watercourse 10 10401 1,383 1,250 61% 51% 10402 509 297 32% 15% Outlet 13 61401 139 157 32% -32% Watercourse 15 15401 3,073 2,604 73% 47% 15402 3,925 3,112 79% 61% Watercourse 31 31401 Unknown1 Unknown1 Outlet 33 33401 Unknown1 20,906 Unknown1 Watercourse 34 34401 1,668 1,744 89% 66% Watercourse 40 40401 2,418 3,396 87% 80% WATERCOURSE / OUTLET SWMF ID ACTIVE STORAGE VOLUME (m3) PEAK FLOW REDUCTION Required Provided 1:5-Year Minor Storm 1:100-Year Major Storm Silver Creek (50) 50401 15,754 16,490 87% 77% 50402 1,746 1,419 77% 66% Watercourse 52 52401 349 671 70% 69% 52402 477 495 51% 41% Little Beaver River (54) 54401 1,502 1,365 94% 94% 54402 5,842 5,440 89% 67% 54404 653 647 82% 90% 54405 624 738 49% 41% Outlet 56 56401 53,139 59,520 48% 10% Outlet 57 57401-42 473 178 56% 59% 1. SWMF information incomplete. SWMFs excluded from VO and PCSWMM models. 2. SWMFs 57401-57404 are in series. The Active Storage presented is the value from the outlet pond (Pond 4 (57401)) Table 10: SWMF Water Quality Assessment Summary WATERCOURSE / OUTLET SWMF ID PERMANENT POOL STORAGE VOLUME (m3) EXTENDED DETENTION VOLUME (m3) EROSION CONTROL VOLUME (m3) TREATMENT LEVEL Required Provided Required Provided Required Provided Watercourse 1 1402 188 298 452 1,284 509 2,096 Enhanced (80%) 1403 1,012 8,631 1,883 7,060 1,181 13,337 Enhanced (80%) Watercourse 6 6401 5,275 46,100 6,157 5,900 5,275 28,000 Enhanced (80%)1, 2 6402 524 4,220 501 1,148 485 2,095 Enhanced (80%) 6403 1,895 8,436 1,328 1,400 3,553 6,000 Enhanced (80%) 6405 1,325 3,625 890 3,915 1,715 3,915 Enhanced (80%) 6406 5,199 26,500 6,291 3,300 5,425 15,800 Enhanced (80%)1, 2 6408 1,990 6,674 2,036 0 1,857 2,798 None 6409 - - 78 193 87 193 Basic (60%) Watercourse 9 9401 1,005 1,350 1,194 587 1,247 1,672 Enhanced (80%)1 9402 1,764 2,722 1,543 2,285 1,614 8,539 Enhanced (80%) Watercourse 10 10401 - - 539 919 623 1,250 Basic (60%) Watercourse 15 15401 1,074 1,377 966 954 770 2,604 Enhanced (80%)1 15402 1,620 414 1,426 1,252 1,638 3,112 Basic (60%)1 WATERCOURSE / OUTLET SWMF ID PERMANENT POOL STORAGE VOLUME (m3) EXTENDED DETENTION VOLUME (m3) EROSION CONTROL VOLUME (m3) TREATMENT LEVEL Required Provided Required Provided Required Provided Watercourse 31 31401 1,793 18,374 1,836 5,877 2,049 Unknown3 Enhanced (80%) Outlet 33 34402 1,130 1,160 1,807 3,930 2,711 20,906 Enhanced (80%) Watercourse 34 34401 261 843 377 846 746 1,744 Enhanced (80%) Watercourse 40 40401 428 1,721 456 2,396 913 3,396 Enhanced (80%) Silver Creek (50) 50401 4,359 6,990 3,472 7,400 4,359 16,490 Enhanced (80%) 50402 - 759 679 759 659 1,419 Enhanced (80%) Watercourse 52 52401 36 5,776 116 331 - 671 Enhanced (80%) 52402 65 4,083 209 244 - 495 Enhanced (80%) Little Beaver River (54) 54401 399 954 276 306 669 1,365 Enhanced (80%) 54402 1,051 8,212 1,051 3,662 1,992 5,440 Enhanced (80%) 54405 - - 700 446 413 738 None Outlet 56 56401 9,799 31,697 12,060 7,338 15,076 59,520 Enhanced (80%)1 Outlet 57 57401-4 1,076 746 890 0 1,170 2,049 None 1. SWMF meets the criteria specified in the MECP SWMPD manual for the level of treatment specified but does not provide extended detention for all runoff from the 25 mm storm. 2. Ponds are in series and together provide sufficient extended detention volume to treat runoff from the 25 mm storm. 3. SWMF information incomplete, active storage unknown. 4.5 CLIMATE CHANGE ANALYSIS The hydrologic and hydraulic analysis of the existing conditions were also conducted using the climate change design storms described in Section 4.2 of the Existing Conditions Report. The minor and major system climate change scenarios produced higher peak flows for all modeled drainage systems resulting in a minor increase in the number of minor and major drainage system deficiencies across the study area. The results of the climate change analysis are presented in Section 6 of the Existing Conditions Report. 5 Future Conditions System Analysis The Town has experienced significant growth through new development and intensification of existing developed areas in recent years, and this is expected to continue into the future. New development and intensification lead to increases in the amount of impervious area which in turn increases surface runoff volume and peak flows placing a greater strain on drainage infrastructure. To appropriately design the alternative solutions considered through this study, the base hydrologic and hydraulic models were updated to account for future land use conditions. 5.1 ANALYSIS METHODOLOGY The greatest impacts to future drainage conditions are expected to be caused primarily by the following three items: 3. Climate change leading to an increase in the intensity and frequency of extreme storm events; 4. New development of existing undeveloped lands leading to an increase in imperviousness and a corresponding increase in surface runoff which will have impacts downstream; and 5. Redevelopment (intensification) of existing developed areas leading to an increase in imperviousness and a corresponding increase in surface runoff which will have impacts downstream. The above three items are accounted for in the future conditions analysis as follows: 1. To account for the effects of climate change, the climate change design storms as described in section 4.2 of the Existing Conditions Report were used for all future conditions analysis conducted as part of this study. 2. The Town has the opportunity to control the impacts of new development on the downstream drainage system by implementing design criteria which requires new development to demonstrate, through hydrologic analysis, that the development causes no negative impacts downstream. The hydrologic model developed for this study can serve as the basis for this analysis in support of future developments. Based on these considerations, the currently undeveloped areas proposed for future development are assumed to maintain existing peak flows post-development in the future conditions analysis. 3. There are limited opportunities in existing developed areas for flow control measures to be implemented to account for the effects of intensification. Therefore, it is assumed increases to imperviousness in these areas will result in the need for infrastructure to be sized to convey increased peak flows. Hence, the imperviousness parameter in the hydrologic models were updated to account for the effect of redevelopment (intensification) to the maximum allowable lot coverage permitted by the Town’s Zoning By-law. The imperviousness values used for different residential zones are summarized in Table 11 below. Table 11: Maximum Residential Lot Coverage and Imperviousness Summary ZONING MAX LOT COVERAGE HYDROLOGIC MODEL IMPERVIOUSNESS R1-1 30% 40% R1-2 35% 45% R1-3 40% 50% R1-4 20% 30% R1-5 - 35% R2 - 60% R3 - 75% Residential subcatchments with imperviousness exceeding the maximum zoning imperviousness under existing conditions were not updated in the future conditions hydrologic analysis. For subcatchments within Commercial, Institutional, Industrial, and Development zoning areas, the hydrologic model subcatchments were not updated as post to pre -development peak flow control will be implemented for those lands. 5.2 HYDROLOGIC ANALYSIS The results of the future conditions major system hydrologic model are summarized in Table 12 and detailed results are included in Appendix F for reference. Table 12: Future Conditions Major Drainage System Model Peak Flow Summary WATERCOURSE / OUTLET AREA (ha) DESIGN STORM PEAK FLOW (m3/s, % Increase) 1:5-YEAR 1:25-YEAR 1:100-YEAR TIMMINS Watercourse 1 Upstream of Spill 239.4 10.8 /28% 18.0 /18% 24.6 /16% 19.9 /2% Downstream of Spill 63.7 2.1 /5% 2.50 /5% 2.9 /5% 3.8 /0% Watercourse 2 32.8 0.4 /49% 0.7 /30% 1.0 /22% 1.2 /2% Watercourse 6 Upstream of Spill 16.1 16.1 /45% 25.3 /36% 33.7 /31% 31.6 /5% Downstream of Spill 2.7 2.7 /292% 4.11 /256% 5.5 /255% 3.0 /8% Watercourse 7 Upstream of Spill 7.9 7.9 /16% 12.7 /10% 16.5 /7% 12.3 /0% Downstream of Spill 0.5 0.5 /42% 0.9 /31% 1.1 /23% 1.0 /5% Outlet 8 19.6 0.6 /19% 0.9 /10% 1.3 /6% 1.3 /-1% Watercourse 9 191.8 7.0 /19% 11.1 /11% 14.8 /9% 14.1 /0% Watercourse 10 67.6 5.6 /28% 8.7 /14% 11.8 /15% 6.4 /2% Outlet 13 81.7 8.3 41% 12.7 29% 16.9 26% 7.9 4% Watercourse 14 93.0 4.5 /19% 7.1 /9% 9.8 /11% 7.9 /1% Outlet 45 31.5 2.1 /27% 3.7 /28% 4.9 /22% 2.5 /1% Watercourse 15 80.0 4.7 /12% 8.2 /16% 12.1 /20% 7.3 /1% Watercourse 18 24.4 1.0 /16% 1.6 /12% 2.3 /9% 1.8 /1% Watercourse 19 341.1 17.4 /21% 29.7 /13% 40.7 /8% 29.0 /0% Watercourse 21 112.2 6.1 /20% 9.6 /12% 13.2 /9% 9.5 /0% Watercourse 22 60.8 2.1 /56% 3.7 /51% 5.1 /46% 4.1 /14% Outlet 23 15.1 0.5 /19% 0.8 /12% 1.1 /9% 1.0 /0% WATERCOURSE / OUTLET AREA (ha) DESIGN STORM PEAK FLOW (m3/s, % Increase) 1:5-YEAR 1:25-YEAR 1:100-YEAR TIMMINS Outlet 24 21.6 0.6 /21% 1.1 /13% 1.5 /10% 1.4 /0% Outlet 25 56.6 3.3 /17% 5.4 /11% 7.1 /8% 5.1 /0% Outlet 26 113.7 5.1 /17% 8.0 /11% 10.5 /8% 9.0 /0% Watercourse 28 56.2 4.0 /20% 6.4 /12% 8.3 /8% 5.0 /1% Watercourse 29 23.4 1.2 /30% 2.0 /17% 2.7 /14% 1.7 /1% Outlet 30 34.8 2.0 /23% 3.3 /13% 4.6 /10% 2.8 /1% Watercourse 31 129.5 7.8 /23% 12.6 /16% 17.3 /16% 11.2 /0% Watercourse 32 352.6 13.9 /17% 22.4 /11% 29.8 /9% 27.2 /0% Outlet 33 60.5 3.0 /23% 5.0 /15% 6.8 /12% 4.4 /2% Watercourse 34 575.5 24.7 /19% 39.0 /8% 50.6 /8% 44.9 /0% Watercourse 40 115.3 1.9 /22% 3.4 /20% 4.8 /18% 5.5 /9% Watercourse 41 14.6 0.6 /17% 1.0 /10% 1.3 /9% 0.8 /0% Watercourse 42 29.0 1.3 /73% 2.1 /78% 2.9 /70% 1.7 /21% Silver Creek North of Holly Court (50) 29.2 0.9 /69% 1.7 /56% 2.3 /32% 2.4 /6% Silver Creek South of Holly Court (50) 199.0 10.3 /7% 15.5 /2% 19.8 /2% 17.0 /0% Silver Creek South of Mount View Court (50) 1,412.3 39.9 /33% 68.6 /28% 93.8 /24% 92.5 /18% Indian Brook (51) 3,544.5 97.1 /18% 157.0 /11% 210.7 /9% 223.8 /0% Watercourse 52 310.0 3.4 /22% 6.1 /14% 8.6 /10% 12.2 /0% Little Beaver River (54) 1,559.7 45.1 /21% 73.8 /14% 98.1 /10% 99.4 /1% Watercourse 55 160.3 8.2 /17% 13.1 /11% 17.4 /8% 13.9 /0% Boulder Channel (56) 311.1 4.5 /21% 11.5 /15% 15.9 /7% 19.0 /-1% As shown in the results summarized in Table 12 above, there is generally a minor to moderate increase in peak flows from the Existing Conditions Analysis for all watersheds under all design storms. 6 Description of Overall Improvement Alternatives For this study, a number of improvement alternatives were considered to address the problem statement and correct the noted deficiencies. The following sections describe the alternatives considered through this study. 6.1 EXISTING CONDITIONS 6.1.1 Alternative 1A – “Do Nothing” Minor Drainage Systems The “Do Nothing” alternative allows for the consideration of not implementing any changes to the existing minor drainage system infrastructure within the study area. This alternative is being considered to provide a benchmark to gauge the physical, natural, social, cultural, and economic implications of the other alternatives. 6.1.2 Alternative 1B – “Do Nothing” Major Drainage Systems The “Do Nothing” alternative allows for the consideration of not implementing any changes to the existing major drainage system infrastructure within the study area. This alternative is being considered to provide a benchmark to gauge the physical, natural, social, cultural, and economic implications of the other alternatives. If this alternative were selected, consideration should be given by the Town to acquiring private properties or interests therein (easements) that are impacted by flooding. 6.2 FLOW REDUCTION/WATER QUALITY IMPROVEMENTS Opportunities exist in the study area to implement SWM measures to attenuate flows, improve water quality and decrease flooding in watersheds throughout the Town. These opportunities include retrofitting, expanding and creating SWM detention facilities and implementing Low Impact Development (LID) measures. The water quality/flow reduction improvement options considered as part of this study are described in the following sections. 6.2.1 Alternative 2A – Retrofit/New Stormwater Management Facilities for Quantity Control An opportunity exists to retrofit and expand existing stormwater management facili ties and construct new stormwater management facilities within the Town to improve water quantity control, attenuate peak flows and reduce downstream flooding. Opportunities exist to expand existing SWMF’s to increase the available storage and decrease release rates into the downstream watercourses and drainage systems. Similarly, end-of-pipe and on-line SWMF’s may be constructed at locations absent of any water quantity controls. Also, the SWMF retrofits and new SWMF’s can be designed to improve watershed water quality, promote infiltration and improve the water balance to meet the objective of Alternative 2B. The implementation of specific SWMF retrofits and creation of new SWMF’s in some cases will require the purchase of private property or acquiring interest therein (easements) to accommodate the improvements, attenuate peak flows, reduce downstream flooding, improve water quality and provide for maintenance access. 6.2.2 Alternative 2B – Retrofit/New Stormwater Management Facilities for Quality Control An opportunity exists to retrofit existing stormwater management facilities and construct new stormwater management facilities within the Town to improve watershed water quality, promote infiltration and improve the water balance. Opportunities exist to retrofit existing dry ponds to include an LID component or convert them into wet ponds or wetlands. Similarly, end -of-pipe SWMF’s may be constructed at locations absent of any water quality controls upstream of existing watercourses. The implementation of specific SWMF retrofits and creation of new SWMF’s will in some cases require the purchase of private property or acquiring interest therein (easements) to accommodate the improvements, improve water quality and provide for maintenance access. 6.2.3 Alternative 2C – Expansion of Existing Floodplain Storage Areas An opportunity exists to expand existing floodplain storage areas upstream of select culvert crossings within the Town to improve water quantity control, attenuate peak flows and reduce downstream flooding. These floodplain storage areas would be activated during major storms and freshets where a culvert crossing creates a backwater effect upstream causing water to flood a storage area. The implementation of specific floodplain storage expansion projects will, in some cases, require the purchase of private property to accommodate the improvements, attenuate peak flows, reduce downstream flooding and provide for maintenance access. 6.2.4 Alternative 2D – Lot Level Low Impact Development An opportunity exists to promote the use of lot level Low Impact Development measures on private property across the Town to promote infiltration, improve the water balance and watershed water quality. Opportunities exist to promote the use of rain barrels and implementation of soakaway pits by residents and property owners in the Town. 6.2.5 Alternative 2E - Linear Low Impact Development An opportunity exists to implement linear Low Impact Development measures to attenuate pe ak flows, promote infiltration, and improve the water balance and watershed water quality throughout the Town. Opportunities exist to implement perforated pipe systems or infiltration systems as part of local road reconstruction projects and intensification in the Town. 6.2.6 Alternative 2F – Centralized Low Impact Development Measures An opportunity exists to implement centralized Low Impact Development measures throughout the Town to attenuate peak flows, promote infiltration, and improve the water balance and watershed water quality. Opportunities exist to implement bio-retention facilities and infiltration galleries within existing parkland and at locations absent of any water quantity or quality controls in the Town. 6.2.7 Alternative 2G – Mechanical Treatment Devices (Oil Grit Separators) An opportunity exists to implement mechanical treatment devices to improve watershed water quality. Specifically, the opportunity exists to install oil grit separators within the minor drainage system storm sewer networks where SWMFs and linear and centralized LIDs are not feasible to treat stormwater. 6.3 CONVEYANCE CAPACITY IMPROVEMENTS There are opportunities in the study area to implement conveyance capacity improvements to reduce flooding on both private and municipal property. These opportunities include culvert improvements, watercourse improvements, major drainage system/overland flow route improvements, minor drainage system improvements, and trunk storm sewer construction. The conveyance capacity improvement options considered as part of this study are described in the following sections. The conveyance capacity improvements considered as part of this study are described in the following sections. 6.3.1 Alternative 3A – Minor Drainage System Improvements Under this alternative, existing under-sized (deficient) storm sewers throughout the Town would be replaced with larger size sewers to satisfy the Town’s design standards and convey the 1:5- year peak flows under the future conditions scenario. Additionally storm sewers and other minor system infrastructure would be relocated from private property onto Town property where required. The existing minor drainage system deficiencies are illustrated on the Minor Drainage System Deficiency Maps (Drawings 1A-1G) and the Storm Sewer Design Standards Deficiency Maps (Drawings 3A-3G) included in the Existing Conditions Report enclosed in Appendix A for reference. An opportunity exists to service areas that currently have no minor drainage systems. Through review of the drainage systems, a number of streets in the study area have been identified that are absent of minor drainage systems. Under this alternative, consideration will be given to service the streets absent of minor drainage systems throughout the study area. 6.3.2 Alternative 3B – Culvert/Watercourse Major Drainage System Improvements Under this alternative, culvert and watercourse improvements can be implemented along the various watercourses throughout the Town to satisfy the Town’s design flood frequency criteria and provide safe access/egress. The roads in the study area are generally classified as local, collector and arterial roads with design flood frequency criteria of 1:25-year, 1:50-year and 1:100- year design storm peak flows, respectively. Similarly, the watercourse improvements would reduce flooding of existing buildings and/or property where feasible. The implementation of specific culvert and watercourse improvements may require the purchase of private properties or acquiring interest therein (easements) to accommodate the improvements, reduce flooding of existing buildings, and provide for maintenance access. The existing culvert crossing deficiencies are illustrated on the Major Drainage System Deficiency Maps (Drawings 2A -2H) and the existing flood inundation limits are illustrated on the Flood Inundation Maps (Drawings 5A- 5H) included in the Existing Conditions Report enclosed in Appendix A for reference. 6.3.3 Alternative 3C – Trunk Storm Sewer/Overland Flow Route Major Drainage System Improvements Under this alternative, at locations throughout the Town with overland flow deficiencies, existing storm sewers would be replaced with trunk storm sewers such that the combined capacity of the trunk storm sewer and the overland flow route is sufficient to convey the 1:100-year design storm peak flows per Town standards. The existing overland flow route deficiencies are illustrated on the Major Drainage System Deficiency Maps (Drawings 2A-2H) included in the Existing Conditions Report enclosed in Appendix A for reference. 6.3.4 Alternative 3D – Drainage Outlet Design, Operation and Maintenance Under this alternative the Town would apply updated design criteria to the design and construction of drainage outlets to Georgian Bay improve their function. Several drainage issues have been observed at drainage outlets across the Town due to high-water levels in Georgian Bay reducing the capacity of the outlet and wave action depositing material which causes blockages to drainage outlets. Implementing standard criteria for new outlets to Georgian Bay will allow for the design of more effective and easier to maintain drainage outlets. Under this alternative, the Town would implement an operation and maintenance program for the many Town-owned drainage outlets across the Town, and proactively seek to acquire property or easements over existing drainage outlets located on private property which convey municipal drainage. 6.3.5 Alternative 3E – Drainage System Operation and Maintenance Under this alternative the Town would formalize their procedure for the inspection, operation and maintenance of Town-owned culvert crossings, stormwater management facilities, and mechanical treatment devices across the Town. This formal inspection, operation and maintenance program will allow the Town to improve its approach to operation and maintenance as records are created which will illustrate which components of the Town’s drainage system require the most frequent attention. 7 Public Consultation - Public Information Centre (PIC#1) For the Town of The Blue Mountains Drainage Master Plan, public consultation was completed in accordance with the Municipal Class Environmental Assessment process outlined in the Municipal Engineers Association (MEA) Municipal Class Environmental Assessment Document (October 2000, as amended in 2007, 2011 and 2015). The public consultation undertaken leading up to and including Public Information Centre #1 (PIC#1) for this study is outlined in the following sections. 7.1 NOTICE OF STUDY COMMENCEMENT AND PUBLIC INFORMATION CENTRE A virtual Public Information Centre #1 (PIC#1) presentation was posted to the project information page on the Town’s website on February 1, 2022. The PIC presented the drainage deficiencies identified through the study and the alternative solutions to the identified issues being considered for implementation. The public was able to provide input/feedback regarding any additional drainage deficiencies not identified through the study, and initial opinions on the improvement options via online comment sheets and emails to the Town and Tatham. Additionally, a virtual Question and Answer session was hosted on February 24, 2022 to provide the public with an opportunity to ask questions and express concerns directly to the Town and Tatham. The PIC presentation materials are enclosed in Appendix G for reference. 7.2 RESULTS OF PUBLIC CONSULTATION The prerecorded PIC#1 presentation received 177 views and 18 people attended the virtual Question and Answer (Q&A) session. 7 Comment sheets and 13 email responses were received from a total of 20 respondents, some of whom also attended the Q&A session. For questions submitted via comments sheets and emails by respondents who did not attend the Q&A session, Tatham answered those questions via email or phone calls. 7.3 IDENTIFIED DRAINAGE ISSUES & CONCERNS Through PIC#1, a number of respondents identified drainage issues they have witnessed in the Town. The following noteworthy drainage issues were identified by the public and interested stakeholders: ▪ Flooding frequently occurs at the east end of Sunset Boulevard; ▪ Relief pipe between Watercourse 7 and Outlet 8 is obstructed and does not function properly; ▪ Watercourse 1 spills across the golf course and causes flooding of Monterra Road and adjacent private properties; ▪ Flooding frequently occurs on private properties adjacent to outlet of Watercourse 7; ▪ Flooding frequently occurs on Hoover Lane adjacent to outlet of Watercourse 32; ▪ Flooding of private properties adjacent to Watercourse 6 near its outlet to Georgian Bay; and ▪ Several private property drainage issues (i.e. lot grading deficiencies) outside the scope of the Drainage Master Plan were identified. 7.4 PUBLIC PREFERENCE Only the 7 respondents who submitted comment sheets identified their preferences regarding the improvement options considered. Table 13 summarizes the number of respondents who supported each of the general improvement options identified on the comment sheets. Table 13: Summary of Respondents’ Preferred improvement Options IMPROVEMENT OPTION NUMBER OF RESPONDENTS 1) Do Nothing 0 (0%) 2) Storm Sewer Improvements 7 (100%) 3) Water Quality/ Flow Reduction Improvements 3 (43%) 4) Conveyance Improvements 6 (86%) 7.5 PRIVATE PROPERTY DRAINAGE ISSUES As mentioned, there were several comments received from the public related to private property drainage issues. Ultimately surface or groundwater related drainage issues on private property or between two or more private properties is the responsibility of the private property owners. Dealing with the issues raised by these comments is outside the scope of this study. However, some general comments and recommendations are presented for consideration. The Town plays a role in reducing private property drainage issues as part of the development review process and the best practice is to minimize the issues during the planning/construction phases. Current practices are to review development applications for conformance to current standards and guidelines. With the Town currently undergoing a period of significant growth, it is important to design new development areas with sufficient measures to prevent future local/private drainage issues. From the comments received and from experience in other locations, we provide the following general recommendations for further consideration by the Town: 1. Basement floors are to be set a minimum of 0.3 meters above seasonal high groundwater levels in new developments as per the Town’s Engineering Standards. However, often times the groundwater monitoring data used in design is insufficient to establish the seasonal high groundwater levels. The Town should consider prescribing the duration of groundwater monitoring required to determine the seasonally high groundwater level. Where that monitoring period cannot be met, the separation between basement grades and estimated seasonally high groundwater levels should be increased. It is recommended that the Town review their standards regarding separation between basement floors and seasonal high groundwater levels and their groundwater monitoring requirements as part of its next standards update. 2. The Draft Town Engineering Standards state storm service connections shall only be provided to properties where development density does not allow for discharge to side yard swales for overland flow. It is recommended that the Town also consider allowing storm service connections in development areas where soils are not conducive to infiltration to reduce the potential for ponding water causing issues on private property. 8 Screening of Improvement Alternatives A pre-screening exercise was completed for the improvement alternatives described in Section 6 to determine which alternatives would be eliminated from consideration, carried forward as general recommendations of this report, or identified for assessment and evaluation on an individual project basis. The pre-screening exercise completed is described in the following sections. 8.1 EXISTING CONDITIONS 8.1.1 Alternative 1A – “Do Nothing” Minor Drainage Systems Alternative 1A represents the “do nothing” alternative and generally does not satisfy the Town’s design standards. Undersized storm sewer can result in frequent nuisance flooding throughout the study area and safety concerns. Municipal infrastructure located on private property is difficult to access and maintain and will require increased maintenance and ultimate ly replacement as the infrastructure continues to age and deteriorate. Areas absent of minor drainage systems are subjected to frequent nuisance flooding, ponding water, and safety concerns. With current climate models predicting increases in the frequency and intensity of significant storm events, future redevelopment resulting in increased runoff in existing developed areas, and due to the extent of the minor drainage system deficiencies throughout the study area, the implementation of this alternative as a general recommendation has been eliminated. However, this alternative will be assessed and evaluated as a baseline comparison for improvements considered on an individual project basis. 8.1.2 8.1.2 Alternative 1B – “Do Nothing” Major Drainage Systems Alternative 1B represents the “do nothing” alternative and generally does not satisfy the Town’s design standards. The assessed property values of the 282 private properties identified within the flood inundation extents total $395,785,000. As the extent of flooding, throughout the Town, is extensive and currently encompasses a significant number of residential properties, the implementation of this alternative as a general recommendation has been eliminated as it is not practical due to public safety concerns and social implications. However, this alternative will be assessed and evaluated as a baseline comparison for improvements considered on an individual project basis. 8.2 FLOW REDUCTION/WATER QUALITY IMPROVEMENTS As previously described, there are opportunities in the study area to implement SWM measures to attenuate and decrease peak flows and improve water quality in watersheds throughout the Town. Opportunities for retrofitting existing stormwater management facilities, creating new stormwater management facilities or centralized LIDs, expanding existing floodplain storage areas and implementing lot level and linear LIDs were considered. The flow reduction/water quality improvements screened as part of this study are described in the following sections. SWMF Retrofit/Expansion/Creation A review and pre-screening of all existing stormwater management facilities within the Town was conducted to identify existing SWMFs where retrofit and/or expansion of the existing SWMF is feasible and has the potential to provide flow reduction and/or water quality improvements. The pre-screening review identified specific existing SWMFs to move forward for evaluation as individual drainage projects. The pre-screening review is presented in Table 14 below and the results of the pre-screening exercise are summarized in Table 15 below. A review of the background information pertaining to land use and existing drainage systems and patterns was conducted to identify potential opportunities for creation of new stormwater management facilities within the Town. A pre-screening evaluation was completed for the SWMF creation opportunities identified to establish those opportunities suitable to move forward for evaluation as individual drainage projects. The SWMF creation opportunities pre-screening evaluation is presented in Table 16 below and the results of the pre-screening evaluation are summarized in Table 17 below. Floodplain Storage Area Expansion A review of the background information pertaining to land use and topography along watercourses throughout the Town was conducted to identify potential opportunities for expansion of floodplain storage areas upstream of culvert crossings. The floodplain storage area expansion opportunities identified are summarized in Table 18 below. Table 14: Existing SWMF Retrofit/Expansion Pre-Screening Summary SWMF ID DRAINAGE AREA (ha) DESCRIPTION PRE-SCREENING REVIEW NOTES FURTHER EVALUATION (Y/N) 1402 4.1 Second Nature Ph. 1 Enhanced treatment level provided. No additional space for expansion. Full SWMF volume being utilized. N 1403 19.7 Second Nature Ph. 3 Enhanced treatment level provided. No additional space for expansion. Full SWMF volume being utilized. N 6401 94.8 Blue Mountain Pond 3 Privately owned pond used for snowmaking water supply and stormwater management. Enhanced treatment level provided. SWMF volume underutilized. Due to private ownership, and PTTW considerations, coordinating modifications would be complicated and likely not of interest to owner. N 6402 5.2 Blue Mountain IROC Privately owned pond. Enhanced treatment level provided. No additional space for expansion. Full SWMF volume being utilized. N 6403 23.7 Snowbridge Privately owned pond. Enhanced treatment level provided. SWMF volume insufficient by small margin. Controls up to 1:25-year design storm. Reduction of 1:100-year flows by 74% in existing configuration. Little additional benefit to providing further control. N 6405 15.6 Monterra Estates Privately owned pond. Enhanced treatment level provided. SWMF volume insufficient. Controls up to 1:25-year design storm. Reduction of 1:100-year flows by 88% in existing configuration. Little additional benefit to providing further control. N 6406 97.3 Blue Mountain Pond 2 Privately owned pond used for snowmaking water supply and stormwater management. Enhanced treatment level provided. Full SWMF volume being utilized. Due to private ownership, and PTTW considerations, coordinating modifications would be complicated and likely not of interest to owner. N SWMF ID DRAINAGE AREA (ha) DESCRIPTION PRE-SCREENING REVIEW NOTES FURTHER EVALUATION (Y/N) 6408 26.5 Fairway Court Privately owned pond. No extended detention. SWMF volume insufficient. Potential to improve quality treatment with outlet retrofit and no pond expansion. Y 6409 0.4 Willow Creek Privately owned pond. Basic treatment level provided. Full SWMF volume utilized. Very small drainage area (0.4 ha). Very little benefit to retrofit due to small drainage area. N 9401 13.4 Craigleith Parking Lot Privately owned pond. Enhanced treatment level provided. SWMF volume insufficient. Improving pond would require outlet retrofit and pond expansion into adjacent parking area. Unlikely to be supported by owner. N 9402 12.0 Orchard Condo Privately owned pond. Enhanced treatment level provided. SWMF volume underutilized. No additional room for expansion. Reduction of 1:100-year peak flows by 69% in existing configuration. Outlet retrofit to further control flows would provide negligible benefit to downstream system. N 10401 6.2 Craigleith Meadows Basic treatment level provided. Space available in SWM Block for expansion. Full SWMF volume insufficient. Further analysis to evaluate impact of expanding SWMF and potentially redirecting some drainage from Craigleith Road to SWMF. Y 10402 3.6 Istvan Lendvay Underground pipe storage. Quality treatment provided by OGS unit downstream of storage. No space for expansion. N 15401 14.2 Georgian Woodlands Enhanced treatment level provided. No additional space for expansion. SWMF volume insufficient, 1:25-year storm discharges via emergency overflow weir. N 15402 9.1 Alpine Basic treatment level provided. Space available in SWM Block for expansion. SWMF volume insufficient. Consider expansion and retrofit to improve quality treatment and storage volume. Y SWMF ID DRAINAGE AREA (ha) DESCRIPTION PRE-SCREENING REVIEW NOTES FURTHER EVALUATION (Y/N) 31401 32.9 Georgian Bay Club 1 Privately owned pond used for irrigation water supply. SWMF information incomplete. Quality and quantity performance unknown. N 33401 45.2 Georgian Bay Club 2 Privately owned pond. SWMF information incomplete. Quality and quantity performance unknown. N 34401 6.2 Georgian Bay Club 3 Privately owned pond. Enhanced treatment level provided. No additional space for expansion. Full SWMF volume utilized. N 40401 11.4 Clarksbury Enhanced treatment level provided. No additional space for expansion. Pond volume underutilized. Drainage area ~ 10% of downstream watercourse drainage area. SWMF located at bottom of watershed, not beneficial to attenuate flows at this location. N 50401 47.0 Windfall Enhanced treatment level provided. No additional space for expansion. SWMF volume fully utilized. N 50402 4.5 Mountain House Privately owned SWMF. Enhanced level treatment provided. No additional space for expansion. SWMF volume insufficient. Controls up to 1:25-year design storm. Reduction of 1:100-year peak flow by 66% in existing configuration. N 52401 2.9 Cedar Pond 2 & 3 Privately owned pond. Enhanced treatment level provided. SWMF volume underutilized. Pond drainage area very small fraction of downstream watercourse drainage area. N 52402 5.2 Cedar Pond 1 Privately owned pond. Enhanced treatment level provided. Full SWMF volume utilized. Pond drainage area very small fraction of downstream watercourse drainage area. N 54401 5.1 Thornbury Meadows Privately owned pond. Enhanced treatment level provided. No additional space for expansion. SWMF volume insufficient. Controls up to 1:50-year design storms. Reduction of 1:100-year peak flow by 94% in existing N SWMF ID DRAINAGE AREA (ha) DESCRIPTION PRE-SCREENING REVIEW NOTES FURTHER EVALUATION (Y/N) configuration. Drainage area small fraction of downstream watercourse drainage area and downstream sewer system drainage area. 54402 22.1 Lora Bay Pond 2 Privately owned pond. Enhanced treatment level provided. SWMF volume insufficient. Reduction of 1:100-year peak flow by 67% in existing configuration. Pond located near downstream end of Little Beaver River watershed, little benefit to further attenuating flows. N 54403 0.3 Foodland Roof Privately owned building rooftop storage. Not feasible for alteration and limited potential benefits. N 54404 1.4 Foodland Underground Underground storage chambers in privately owned parking lot. Full storage volume utilized. Drainage area small fraction of downstream system drainage area, limited benefit to retrofit/expand. N 54405 3.8 Bluewater Storage Privately owned dry pond. No water quality treatment provided. Drainage area very small fraction of downstream watercourse drainage area, limited benefit to retrofit/expand. N 56401 301.5 Lora Bay Pond 1 Privately owned pond used for stormwater management and irrigation water supply. Enhanced treatment level provided. Full SWMF volume utilized. Pond located very close to Georgian Bay, no benefit to further attenuating flows. N 57401-42 9.4 Keepers Cove Privately owned SWM and aesthetic pond with feed from Georgian Bay and recirculation system. No water quality treatment provided. SWMF volume insufficient. SWMF discharge very close to Georgian Bay, no benefit to further attenuating flows. N 61401 2.1 Sleepy Hollow Stormtech Underground chambers below swale with storage component. No water quality treatment provided. No additional space for expansion. Full SWMF volume utilized. N Table 15: Existing SWMF Pre-Screening Results Summary SWMF ID DESCRIPTION RETROFIT GOAL 10401 Craigleith Meadows Dry Pond Quality Treatment and Quantity Control 15402 Alpine Flatlands SWMF Quality Treatment and Quantity Control 6408 Fairway Court SWMF Quality Treatment Table 16: SWMF Creation Opportunity Pre-Screening Summary SWMF NO. LOCATION DESCRIPTION POTENTIAL DRAINAGE AREA (ha) FURTHER EVALUATION 1 205 Timmins Street Quality treatment SWMF in parkette. Low lying area likely with high groundwater. Approx. 0.1 ha available for SWMF, would require removal of trees. Limited by flat ditch grades and downstream culvert crossing. 5.9 N 3 Plan 915 Pt Block B Lot 17 Quality treatment SWMF in park block. Located at ditch outlet to Watercourse 1. Drainage area currently untreated. 5.7 Y 4 Plan 915 Pt Block B Lot 17 / 332 Jozo Weider Blvd Quantity control SWMF in open space block (with potential for private property acquisition) to attenuate high flows from sewer along Gord Canning Drive. Potential SWMF area = 0.6 ha or 1.1 ha with property acquisition (332 Jozo Weider Boulevard). Runoff primarily from escarpment, peak flows already reduced by 73% by existing SWMFs 6401 and 6406. 52.9 N 5 796338 Grey Road 19 (Fire Hall) Quality treatment SWMF to treat parking lot runoff and Wintergreen Place runoff. Potential SWMF area = 0.2 ha. Located in Fairway Court SWMF watershed, this SWMF not necessary if Fairway Court SWMF retrofitted to provide quality treatment. 4.7 Y SWMF NO. LOCATION DESCRIPTION POTENTIAL DRAINAGE AREA (ha) FURTHER EVALUATION 6 101 Crossan Court (Boyer Park) Potential underground quality SWMF or LID (requires confirmation of soil suitability). Tennis courts appear to have been recently replaced. More viable SWMF creation option in Heritage Park nearby. 13.5 Y 7 Heritage Park (Kandahar Lane) Potential quality and quantity SWMF in park would receive runoff from Settler's Way & Arlberg Crescent. Potential SWMF area 0.2-0.5 ha. 12.8 Y 8 138 Kandahar Lane New SWMF or LID. Requires property acquisition. Located in area zoned for development. Existing drainage area primarily undeveloped. Assume area will have SWM controls when developed. 10.6 N 9 108 Tyrol Lane Quality SWMF to treat small local area. Requires property acquisition. Vacant residential land zoned as open space. Potential SWMF area = 0.1 ha. 10.5 Y 10 Plan 822 Pt Block A Part Lot 66; Georgian Woodlands (St. Moritz Crescent) Redirect Sleepy Hollow Road storm sewer for quality treatment. Requires property acquisition. Existing site topography ~ 8% slope. Would require improvements to St. Moritz Crescent drainage system downstream. Large undeveloped (escarpment) drainage area contributing. OGS installation along storm sewer more viable option for quality treatment. 54.0 N 11 141 Wyandot Court Small open space block (0.2 ha). Upstream drainage area primarily escarpment. No downstream sewer deficiencies. Limited opportunity for impactful improvement. 10.4 N 12 Grey Common Elements Condo; Plan 62 Level 1 (Blueski George Crescent) Potential quality SWMF. Requires property acquisition. Condominium lands with existing private dry pond (unmaintained). Redirect portion of Sleepy Hollow Road sewer flows. 31.0 Y 17 Thornbury Town Plot Pt Lots;15 To 19 Part Quality SWMF or LID. Potentially requires property acquisition. Redirect King Street storm sewer for treatment. ~0.1 ha available for SWMF/LID. 12.4 N SWMF NO. LOCATION DESCRIPTION POTENTIAL DRAINAGE AREA (ha) FURTHER EVALUATION McAuley Street RP;16R8184 Parts 2 and 4 Only 155 m of sewer downstream. Insufficient area for effective SWMF/LID. 19 76 Elma Street & 74 Elma Street Quantity SWMF considered in Thornbury West Drainage Master Plan (TWDMP) project. Dry pond SWMF to provide attenuation of spill from Alfred Street W minor drainage system. Option not recommended by TWDMP, preferred alternative included trunk sewer construction on Victoria Street. 21.6 N 20 58 Alfred Street W (Beaver Valley Community Centre) Quantity SWMF considered in TWDMP project. Underground storage to provide attenuation of spill from Alfred Street W minor drainage system. Option not recommended by TWDMP, preferred alternative included trunk sewer construction on Victoria Street. 21.6 N 21 128 Alfred Street W LID considered in TWDMP project. Located near downstream end of sewer system. Underground infiltration LID to provide quality and quantity control for 25 mm storm. Option not recommended by TWDMP due to impacts on park property, heritage impacts, and construction and maintenance costs. 41.1 N 22 Town Plot Lot 37 to 39 Pt;Lot 36 Arthur E/S Pt Lot 36;To Pt Lot 39 King W/S RP;16R3878 Part 1 Quantity SWMF and LID considered in TWDMP project. Located at downstream end of sewer system. Wet pond SWMF to provide attenuation for 1:5-year flows. Underground infiltration LID to provide quality and quantity control for 25mm flows. Options not recommended by TWDMP due to property acquisition requirement and cost, construction cost, and little benefit to downstream flooding issues. 25.3 N 23 Plan 16M53 Block 76 Quality SWMF or LID. Redirect storm sewer for treatment. ~0.1 ha available for SWMF/LID. Storm sewer already treated by OGS unit downstream. No storm sewer deficiencies downstream. 3.4 N Table 17: SWMF Creation Opportunities Pre-Screening Results Summary SWMF ID LOCATION TYPE OF SWMF 3 Plan 915 Pt Block B Lot 17 (Carmichael Crescent) Quality Treatment 5 796338 Grey Rd 19 (Fire Hall) Quality Treatment 7 Heritage Park (Kandahar Ln) Quality Treatment & Quantity Control 9 108 Tyrol Ln Quality Treatment 12 Grey Common Elements Condo; Plan 62 Level 1 (Blueski George Cr) Quality Treatment Table 18: Expansion Floodplain Storage Areas Pre-Screening Summary ID NO. LOCATION DESCRIPTION POTENTIAL DRAINAGE AREA (ha) FURTHER EVALUATION 2 302 Grey Road 21 Raise Georgian Trail to improve existing wetland floodplain storage and quantity control. Improve roadside ditches along Monterra Road to convey spill from WC1 to WC6. Improve WC6 floodplain from Monterra Road to wetland to contain flow and reduce flooding. Create overland flow route along Georgian Trail to west of Lakeshore Road to convey high flows. Create new outlet at 209741 Highway 26 and/or improve Outlet 8. 493.3 Y 13 205 Blueski George Crescent Create floodplain storage for WC 14 to reduce flows through properties downstream. 5 deficient culverts downstream. 7 properties in floodplain beyond the watercourse. 73.6 Y 14 209403 Highway 26 Create additional floodplain storage to attenuate peak flows downstream and improve culvert performance. Requires property acquisition. 4 309.5 Y ID NO. LOCATION DESCRIPTION POTENTIAL DRAINAGE AREA (ha) FURTHER EVALUATION deficient culverts downstream 7 properties in floodplain beyond watercourse. More properties affected by spill. 15 209403 Highway 26 Create additional floodplain storage to attenuate peak flows downstream and improve culvert performance. Requires property acquisition. 4 deficient culverts downstream (2 in campground). Campground property affected by spill. Limited infrastructure and properties downstream to benefit from improvements. 109.9 Y 16 Con 8 S E Pt Lot 27 RP;16R2484 Pt 2 Create additional floodplain storage to attenuate peak flows downstream and improve culvert performance. Requires property acquisition. 4 deficient culverts downstream. 10 properties in floodplain beyond watercourse. ~ 6.0 ha available for SWMF. Very large drainage area. 509.3 Y 8.2.1 Alternative 2A – Retrofit/New Stormwater Management Facilities for Quantity Control As summarized in Tables 14 and 15 above, the following SWMFs will be assessed and evaluated as individual drainage projects under Alternative 2A: ▪ 10401 (Retrofit) ▪ 15402 (Retrofit) ▪ 6405 (Retrofit) ▪ 3 (Creation) ▪ 5 (Creation) ▪ 7 (Creation) ▪ 9 (Creation) ▪ 12 (Creation) 8.2.2 Alternative 2B – Retrofit/New Stormwater Management Facilities for Quality Control As summarized in Tables 16 and 17 above, the following SWMFs will be assessed and evaluated as individual drainage projects under Alternative 2A: ▪ 10401 (Retrofit) ▪ 15402 (Retrofit) ▪ 7 (Creation) 8.2.3 Alternative 2C – Expansion of Existing Floodplain Storage Areas All floodplain storage area expansion opportunities identified in Table 18 above are to be carried forward for evaluation as individual drainage projects under Alternative 2C. 8.2.4 Alternative 2D – Lot Level Low Impact Development Measures An opportunity exists to promote individual lot level soakaway pits and rain barrels across the Town. There are no constraints on the application of rain barrels. There are also very few constraints on the application of lot level soakaway pits. Soakaway pits should be targeted to areas with soil types that are favourable for infiltration and should not receive runoff from pollution hotspots to protect groundwater from possible contamination. As part of the work completed for the 2019 Thornbury West Drainage Master Plan (TWDMP), a detailed evaluation of the impact of lot level LIDs on infiltration, runoff and peak flows was completed. The application rate of rain barrels or soakaway pits was assumed to be 1 in 4 roofs in residential areas with 25% of the roof area directed to the rain barrel or soakaway pit. The impact on peak flows was assessed for each drainage area in the TWDMP study area. For the 1:100-year return frequency design storm the impact on peak flows was negligible and for the 25 mm storm the maximum percentage decrease in peak flows was 2%. Similarly, the impact on infiltration and runoff across the various drainage areas is considered negligible. For each storm event analyzed, the impact on infiltration and runoff was less than 0.1 mm on an area -weighted basis. From the results of this previous analysis, it is concluded that further detailed numeric analysis of the impact of rain barrels or soakaway pits for the additional settlement areas in the Town will provide very little benefit. Neither measure is expected to impact water quantity control requirements or peak flows in drainage systems. Regardless, rain barrels can reduce residential water use for irrigation and soakaway pits can provide water balance benefits across the watershed and they should be encouraged for these benefits. Implementation of Alternative 2D through public awareness campaigns and marketing is recommended to be carried forward as a general recommendation of this study and further details will be provided in Section 10 of this report. 8.2.5 Alternative 2E - Linear Low Impact Development Measures Opportunities exist to construct linear LIDs within the municipal road allowance as part of road reconstruction and future development. A pre-screening process was undertaken to identify roads within the settlement areas which would be suitable for LID implementation. The pre- screening process considered the following criteria: ▪ Provincial (Highway 26), County, and private roads have been considered as ineligible for LID implementation; ▪ To ensure sufficient separation of the LID measures from the groundwater table near Georgian Bay, LIDs have not been considered for roads below an elevation of 182.00 m; ▪ Roads adjacent to commercial, institutional and industrial zones will be considered for non- infiltration type LIDs to avoid groundwater contamination in these areas where runoff typically has higher concentrations of pollutants; ▪ The length of road for LID Application was determined by applying a factor of 0.60 to the total length of eligible road in each subcatchment. This factor accounts for driveways and sections of road upstream of storm sewers where LID measures will not be installed. ▪ Consideration was not given to the steep slopes observed along some roads in the Town. LIDs are generally recommended to have gentle slopes of 0.5% - 1.0% and therefore some roads with greater slopes considered eligible for LIDs in this assessment may face constructability concerns. The pre-screening process undertaken for this LID assessment is a general high-level assessment meant to provide a preliminary estimate of areas where LIDs can be successfully implemented. It is important that LIDs be assessed on a project-by-project basis at detailed design to ensure the site conditions are suitable for implementation of LID measures. To analyze the impact of implementing linear LIDs within the Town, the minor system PCSWMM hydrologic/hydraulic model was updated to include linear LID Controls for subcatchments draining to a road which was identified as eligible for LID implementation. The PCSWMM model created to assess the linear LIDs has been digitally submitted with this report in Appendix K. Detailed model results may be accessed from the digital model and the results are summarized in Table 19 below. For this study, typical perforated pipe and infiltration trench systems, for urban and rural road cross sections respectively, were designed to model the potential impacts of widespread implementation. Conceptual design details are included in Appendix I for reference. Implementation of linear LID measures is assumed to occur within the municipal road allowance only for local roads identified through the pre-screening process described above. The LID footprint area for each subcatchment is based on a 1.4 m wide linear LID applied to 60% of the eligible road length in the subcatchment. Based on these criteria, 51.4 km road within the study area was identified as eligible for LID implementation for the purposes of this study. As the LIDs will be incorporated into the storm sewer or ditch systems, the entire subcatchment area is assumed to drain to the linear LID. The depth of the LID is assumed to be 900 mm and the height of the LID drain is calculated based on a design infiltration rate and a drawdown time of 48 hours with a maximum drain height of 625 mm. A detailed description of the design parameters, usage characteristics and methodology of application for the PCSWMM modelling of linear LID’s is included in Appendix I. The results of the analysis for the linear LID application are summarized in the following table: Table 19: Linear LID Flow Reduction Results Summary for Select Watersheds WATERSHED/ DRAINAGE AREA PEAK FLOW REDUCTION (m3/s, %) 25 mm STORM 1:5-YEAR STORM 1:100-YEAR STORM Watercourse 10 -0.036 -6.7% -0.045 -3.4% -0.006 -0.2% Outlet 13 -0.238 -13.5% -0.369 -10.1% -0.065 -1.0% Outlet 45 -0.236 -33.7% -0.152 -14.4% -0.015 -1.0% Watercourse 22 -0.112 -51.1% -0.142 -37.3% -0.077 -11.2% Silver Creek S of Holly Ct. (50) -0.104 -10.6% -0.036 -1.3% -0.076 -1.0% Arthur St. W -0.056 -9.0% -0.145 -15.7% -0.074 -5.9% Cameron St. -0.431 -43.6% -0.334 -18.0% -0.047 -1.7% Elgin St. -0.157 -19.1% -0.059 -5.4% -0.044 -3.4% Louisa St. E 0.005 0.8% 0.017 2.3% 0.017 2.0% Alfred St. W -0.373 -32.0% -0.196 -11.6% -0.033 -1.7% Victoria St. -0.331 -34.4% -0.524 -27.7% -0.266 -9.6% The results presented in Table 19 are for watersheds where more than 50% of the watershed area drains to the LIDs as these watersheds would see the greatest impact from linear LID implementation. As shown, the linear LID measures have a limited impact on the major storm event peak flows. However, linear LID measures have the potential to improve peak flow attenuation for minor storm events and reduce frequent nuisance flooding. Full summaries of the evaluation completed for the 25 mm, 1:5-year, and 1:100-year design storms are included in Appendix I for reference. A preliminary construction cost estimate has been prepared for improvement Alternative 2E. The construction cost estimate assumes that construction of the linear LID system is completed as part of road reconstruction and storm sewer replacement. Across the entire study area, the cost estimate for installation of a perforated pipe system on 51.4 km of eligible local roads is $25,906,000 as detailed in Appendix J. Implementation of Alternative 2E is recommended to be carried forward as a general recommendation of this study and further details will be provided in Section 10 of this report. 8.2.6 Alternative 2F – Centralized Low Impact Development Measures Opportunities to construct centralized LID measures and convert existing SWMFs to centralized LID measures were explored through the pre-screening process undertaken for alternatives 2A and 2B. Through this process, there were no centralized LID opportunities identified for further assessment and evaluation as individual drainage projects. 8.2.7 Alternative 2G – Mechanical Devices (Oil Grit Separators) There is an opportunity to install mechanical devices (oil grit separators) within the minor drainage system to treat stormwater and improve water quality where SWMFs , linear LIDs, or centralized LIDs are not feasible. Specific locations/projects were not identified under this improvement alternative. It is recommended this alternative be carried forward as a general recommendation of this study and further details will be provided in Section 10 of this report. 8.3 CONVEYANCE CAPACITY IMPROVEMENTS 8.3.1 Alternative 3A – Minor Drainage System Improvements There is an opportunity to improve the existing storm sewer system throughout the Town to satisfy Town standards and convey the 1:5-year return period peak flows under future conditions. Beyond upsizing, there are also opportunities to address the minimum sewer diameter and slope deficiencies and to remove municipal drainage infrastructure from private property by relocating it within the municipal road allowance. The PCSWMM minor drainage system hydrologic/hydraulic model was updated with storm sewers upsized to convey the future condition 1:5-year peak flows, and existing geometry deficiencies rectified. The PCSWMM digital model files are enclosed for reference. Detailed model results may be accessed from the digital files. A construction cost estimate was prepared for this alternative to compare the difference in price between straight replacement of the existing storm sewer and replacement with storm sewer which satisfies the Town’s design standards. The total cost for straight replacement of all storm sewer within the study area was calculated to be $67,614,700, while the total cost to replace all storm sewer to satisfy Town design standards was calculated to be $75,860,900. Therefore, the cost to replace all storm sewer in the study area to satisfy Town standards is $8,246,200 or a 12% increase from the cost of straight replacement. The detailed cost estimate is included in Appendix J for reference. There is also an opportunity to service areas that currently have no minor drainage system. Specific projects were not identified under this improvement alternative. It is recommended this alternative be carried forward as a general recommendation of this study and further details will be provided in Section 10 of this report. 8.3.2 Alternative 3B – Culvert/Watercourse Major Drainage System Improvements There is an opportunity to implement culvert crossing and watercourse improvements along the various watercourses throughout the Town to satisfy the Town’s design flood frequency criteria, provide safe access/egress for vehicles and reduce the extents of flooding. The culvert and watercourse improvements considered through this study are described in the following sections. Culvert Improvements In addition to the Town standard design flood frequency criteria and the safe access/egr ess criteria, culvert improvements must also consider feasibility of construction and potential reductions to peak flows from flow reduction improvements. To ensure all potential culvert improvement options for a given culvert crossing are considered, the following culvert improvement scenarios were considered: 1. Scenario A – Culvert sized to satisfy Town standard flood frequency criteria. 2. Scenario B – Culvert sized beyond Town standard to satisfy safe access/egress criteria. 3. Scenario C – Culvert sized to satisfy Town standard flood frequency criteria considering proposed flow reduction improvements. 4. Scenario D – Culvert sized beyond Town standard to satisfy safe access/egress criteria considering proposed flow reduction improvements. 5. Scenario E – Culvert sized to be feasibly constructed without significant upstream and/or downstream channel improvements but does not satisfy Town standards. 6. Scenario F – Do nothing option used for comparison to the proposed culvert upgrades. 7. Scenario G – Culvert sized beyond Town standard to maintain conveyance capacity of upstream crossings, or culvert sized less than Town standard to maintain conveyance capacity of downstream crossings. Culvert improvements designed per Scenario A which satisfy the safe access/egress criteria were not considered under Scenario B. Scenarios C and D were only considered for those culvert crossings which are downstream of contemplated flow reduction improvements under Alternatives 2A, 2B and 2C. Scenario E was considered for culvert crossings which require improvements to the watercourse beyond the right of way to accommodate a Scenario A culvert crossing, and for crossings where installing a Scenario A culvert represents a significant upgrade in culvert capacity from existing which could potentially have negative downstream impacts. Culvert crossing improvements were assessed and evaluated on an individual project basis. Watercourse Improvements Watercourse improvements were considered where feasible and necessary to accommodate recommended culvert improvements, and in locations where there is currently significant risk to private property which can be reduced through watercourse improvements. Watercourse improvements will also be considered at select locations identified by the geomorphology report prepared by Water’s Edge to stabilize the channel and prevent potentially dangerous erosion from continuing. Some watercourse improvements were assessed and evaluated as part of the individual culvert crossing improvement projects while others were assessed and evaluated through specific individual drainage projects. 8.3.3 Alternative 3C – Trunk Storm Sewer/Overland Flow Route Major Drainage System Improvements There is an opportunity to implement trunk storm sewer improvements at specific locations throughout the Town such that the combined capacity of the trunk storm sewer and the overland flow route is sufficient to convey the 1:100-year design storm peak flows in accordance with Town standards. The following locations with existing overland flow route deficiencies were identified as potential trunk storm sewer improvement projects: 1. East Ridge Drive (Lora Bay); 2. King Street East (Thornbury); 3. Camperdown Road (Camperdown); 4. Arrowhead Road (Craigleith); and 5. Jozo Weider Boulevard/Lucille Wheeler Crescent (Blue Mountain). Each of the aforementioned trunk storm sewer improvement projects were assessed and evaluated on an individual project basis. 8.3.4 Alternative 3D – Drainage Outlet Design, Operation and Maintenance There is an opportunity for the Town to apply updated design criteria to the design and construction of drainage outlets to Georgian Bay to improve their function. Where feasible, outlets should be set back from the shoreline and set at a sufficient elevation to be protected from wave uprush that can result in damage to outlet structures and deposition of material which obstructs flows. There is also an opportunity for the Town to implement a regular, comprehensive inspection, operation and maintenance program for the many Town-owned drainage outlets across the Town. The Town has previously completed inspections of 20 outlets across the Town during periods of high water levels in Georgian Bay and the Town should proactively seek to acquire property or easements across private property over drainage outlets under this alternative. It is recommended that this alternative be carried forward as a general recommendation of this study and further details will be provided in Section 10 of this report. 8.3.5 Alternative 3E – Drainage System Inspection, Operation and Maintenance There is an opportunity for the Town to formalize their procedure for the inspection, operation and maintenance of Town-owned culvert crossings, stormwater management facilities, and mechanical treatment devices across the Town. This formal inspection, operation and maintenance program will allow the Town to improve its approach to operation and maintenance as records are created which will illustrate which components of the Town’s drainage system require the most frequent attention. It is recommended that this alternative be carried forward as a general recommendation of this study and further details will be provided in Section 10 of this report. 9 Individual Drainage Projects Assessment and Evaluation The individual projects identified under each recommended Alternative Solution presented in Section 8 were evaluated on a watershed-by-watershed basis with respect to their impact on the physical, natural, social, cultural and economic environments presented in Section 3. To assess the effectiveness of the individual drainage projects considered, the existing conditions minor and major drainage system models of the study area have been revi sed to include the proposed projects. The results of the analysis, specifically the reductions in peak flows and flooding impacts under each improvement alternative are discussed in the subsequent sections. For select projects, specifically Schedule B projects, several options were evaluated to establish the option that produced the greatest positive impact on the project environments. The evaluation of each option is presented on the subsequent sections. Qualitative and quantitative evaluations were completed allowing for a comparative evaluation of the pros and cons associated with each project. The evaluation is focused on the ability of the individual projects to adequately address the problem statement, and in doing so, provide a solution that is consistent with the requirements of the governing policies. The individual project evaluation completed is provided in the following table. The locations of the individual projects evaluated are illustrated on the Alternative Solutions Maps (Drawings 7A – 7H) provided overleaf. The digital model files supporting the individual drainage projects assessment are included in Appendix K for reference. Recommended Project Feasible Project (Conditional) Not Recommended/Not Feasible Recommended Project Feasible Project (Conditional) Not Recommended/Not Feasible Recommended Project Feasible Project (Conditional) Not Recommended/Not Feasible Recommended Project Feasible Project (Conditional) Not Recommended/Not Feasible Recommended Project Feasible Project (Conditional) Not Recommended/Not Feasible Recommended Project Feasible Project (Conditional) Not Recommended/Not Feasible IGEORGIAN BAY I N AN I GEORGIAN BAY I TOWN OF COLLINGWOOD LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) EXISTING SWMF RETROFIT (QUANTITY)~ EXISTING SWMF RETROFIT (QUALITY AND ~ QUANTITY) PROPOSED SWMF CREATION (QUALITY)■ PROPOSED SWMF CREATION (QUANTITY)■ ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE (§_) CULVERT ID s SWMF/ LID/ STORAGE AREA ID [TI ALTERNATIVE SOLUTION ID -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -• BOULDER CHANNEL STUDY AREA -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.45 0.6 Kilometers - ---- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN THIS DRAWING IS SOLELY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEERING LTD . UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHAM ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: BOULDER CHANNEL DRA INAGE IMPROVEMENTS AS SHOWN WERE RECOMMENDED AS PART OF THE LORA BAY DEVELOPMENT SWM POND NO. 1 STORMWATER MANAGEMENT REPORT (TATHAM ENGINEERING LIMITED, DECEMBER 2021). ADDITIONAL DRAINAGE IMPROVEMENTS IN THE LORA BAY DEVELOPMENT LANDS WILL BE DEVELOPED AS PART OF THE MASTER DEVELOPMENT PLAN FOR THESE LANDS No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER PLAN (60% SUBMISSION) SEPT 2022 ALTERNATIVE SOLUTIONS MAP DESIGN: JM FILE: 121076 DWG: 7ADRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1:5000 N A N I GEORGIAN BAY I BLUE MOUNTAIN TOWN OF VILLAGE CO LLINGWOOD IGEORGIAN BAY I LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) EXISTING SWMF RETROFIT (QUANTITY)~ THORNBURY WEST DRAINAGE MASTER EXISTING SWMF RETROFIT (QUALITY AND PLAN IMPROVMENTS AREA (SEE NOTE) ~ QUANTITY) PROPOSED SWMF CREATION (QUALITY)■ PROPOSED SWMF CREATION (QUANTITY)■ ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE (§_) CULVERT ID s SWMF/ LID/ STORAGE AREA ID ~ ALTERNATIVE SOLUTION ID -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -• THORNBURY WEST END DRAINAGE STUDY AREA -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.45 0.6 Kilometers DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN T HI S DRAW ING IS SOLELY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEER ING LTD . UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN T HAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, R E PRODUCED ELECTRONICALLY STORED OR TRANSMITT ED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: D RAINAGE IMPROVEMENTS IN THORNBURY WEST END STUDY AREA RECOMMENDED THROUGH THORNBURY WEST DRAINAGE MASTER PLAN MUNICIPAL CLASS EA (TATHAM ENGINEER ING LIMITED, MARCH 2019) No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER P LAN (60% SUBMISSION) SEPT 2022 ALTERNATIVE SOLUTIONS MAP DESIGN: JM FILE: 121076 DWG: 7BDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1 :5000 N Atv I GEORGIAN BAY I 11;.,,, nn.: LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) EXISTING SWMF RETROFIT (QUANTITY)~ EXISTING SWMF RETROFIT (QUALITY AND ~ QUANTITY) PROPOSED SWMF CREATION (QUALITY)■ PROPOSED SWMF CREATION (QUANTITY)■ PROPOSED SWMF CREATION (QUALITY AND ■ QUANTITY) PROPOSED CENTRALIZED LID■ PROPOSED EXPANSION OF FLOODPLAIN■ STORAGE @ CULVERT ID 8 SWMF/ LID/ STORAGE AREA ID G:) ALTERNATIVE SOLUTION ID -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -• THORNBURY WEST END DRAINAGE STUDY AREA -WATERCOURSE ~ SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.6 Kilometers ------- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN THIS DRAWING IS SOLE LY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEERING LT D. UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: D RAINAGE IMPROVEMENTS IN THORNBURY WEST END STUDY AREA RECOMMENDED THROUGH THORNBURY WEST DRAINAGE MASTER PLAN MUNICIPAL CLASS EA (TATHAM ENGINEER ING LIMITED, MARCH 2019) No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER P LAN (60% SUBMISSION) SEPT 2022 ALTERNATIVE SOLUTIONS MAP DESIGN : JM FILE: 121076 DWG: 7CDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1 :5000 IGEORGIAN BAY I N A N I GEORGIAN BAY I TOWN OF COLLINGWOOD LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) ~ EXISTING SWMF RETROFIT (QUANTITY) ~ EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @ CULVERT ID 8 SWMF/ LID/ STORAGE AREA ID [!J ALTERNATIVE SOLUTION ID -• WATERCOURSE IMPROVEMENT -• OVERLAND FLOW ROUTE IMPROVEMENT -WATERCOURSE ~ SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.6 Kilometers ------- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN T HIS DRAWING IS SOLE LY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEER ING LT D. UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER PLAN (60% SUBMISSION) SEPT 2022 ALTERNATIVE SOLUTIONS MAP DESIGN : JM FILE: 121076 DWG: 7DDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1 :5000 LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) ~ EXISTING SWMF RETROFIT (QUANTITY) ~ EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @) CULVERT ID €3 SWMF/ LID/ STORAGE AREA ID [!J ALTERNATIVE SOLUTION ID -• WATERCOURSE IMPROVEMENT -• OVERLAND FLOW ROUTE IMPROVEMENT -• DRAINAGE ACT IMPROVEMENT AREA WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION a'.: ' --' N u.J ~ ::::, IGEORGIAN BAY I NOW p 0 0.07 0.15 0.3------ I GEORGIAN BAY I 0.45- N A 0.6 Kilometers DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN T HIS DRAWING IS SOLE LY FOR THE USE OF THE TOWN OF T HE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENG INEERING LT D. UN DE RTAKES NO DUTY OR ACCEPTS ANY RESPONSIB ILITY TO ANY THIRD PARTY WHO MAY RE LY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN O F THE BLUE MOUNTAINS AND TATHAM ENGINEER ING LTD NOR MAY ANY DETA IL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRON ICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN O F THE BLUE MOUNTAINS NOTE: DRAINAGE IMPROVEMENTS IN THE PARKBRIDGE , EDEN OAK AND MACPHERSON LANDS RECOMMENDED THROUGH THE REGIONA L STORMWATER MANAGEMENT PLAN -BLUE MOUNTA IN DIVERSION DRAIN -DRAINAG E ACT ASSESSMENT RE PO RT (WT INFRAS T RUCTU R E, MAR CH 2022) . No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLANDRAINAGE MASTER PLAN (60% SUBMISSION) SEPT 2022 ALTERNATIVE SOLUTIONS MAP DESIGN : JM FI LE: 121076 DWG: 7EDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1 :5000 DRAINAGE ACT IMPROVMENT AREA (SEE NOTE) GEORGIAN BAY N A I GEORGIAN BAY I LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) ~ EXISTING SWMF RETROFIT (QUANTITY) ~ EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @ CULVERT ID €140~ SWMF/ LID/ STORAGE AREA ID DJ ALTERNATIVE SOLUTION ID -• WATERCOURSE IMPROVEMENT -• OVERLAND FLOW ROUTE IMPROVEMENT -• DRAINAGE ACT IMPROVEMENT AREA -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.45 0.6 Kilometers ------- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN THIS DRAWING IS SOLE LY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEERING LT D. UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: DRAINAGE IMPROVEMENTS IN THE PARKBRIDGE , EDEN OAK AND MACPHERSON LANDS RECOMMENDED THROUGH THE REGIONAL STORMWATER MANAGEMENT PLAN -BLUE MOUNTAIN DIVERSION DRAIN -DRAINAGE ACT ASSESSMENT REPORT (WT INFRASTRUCTURE, MARCH 2022) . No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLANDRAINAGE MASTER PLAN (60% SUBMISSION) SEPT 2022 ALTERNATIVE SOLUTIONS MAP DESIGN : JM FILE: 121076 DWG: 7FDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1 :5000 . • • 4 • ••• • ••• • ••.. • ••• • •••• ' .-'·•C' . ••.,' ,.• '. •,· .....,.__,., ' .~ -. ...•,, ., ' N A I GEORGIAN BAY I LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT -• PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) ~ EXISTING SWMF RETROFIT (QUANTITY) ~ EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @ CULVERT ID €140~ SWMF/ LID/ STORAGE AREA ID DJ ALTERNATIVE SOLUTION ID -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0,3 0,6 Kilometers ------- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN THIS DRAWING IS SOLE LY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEERING LT D. UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: No, REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER PLAN (60% SUBMISSION) SEPT 2022 ALTERNATIVE SOLUTIONS MAP DESIGN : JM FILE: 121076 DWG: 7GDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1:5000 N A I GEORGIA N BAY I TH ORN BU RY \ ,. K_EY PLAN LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) ~ EXISTING SWMF RETROFIT (QUANTITY) ~ EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @ CULVERT ID €140~ SWMF/ LID/ STORAGE AREA ID DJ ALTERNATIVE SOLUTION ID -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0. 3 0.6 Kilometers ------- DISCLAMER AND COPYRIGHT T HE IN FORMAT ION CONTA INED IN T HI S DRAW IN G IS SO LELY FO R T H E USE O F T HE TOW N O F THE BLUE MOUNTA IN S FOR T HE PU RPOSE FO R W HI C H IT HAS BEEN P REPA RED A N D TATHAM EN GI N EER ING LTD . UNDE RTAKES NO DUTY O R ACCE PT S A NY RES PO NSIBILI T Y TO A NY T H IR D PART Y WHO M AY R ELY UPO N T HIS DRAWI NG. T HI S D RAW IN G MAY NOT B E USED F OR ANY PURPO SE OTHER T HA N T HAT PR OV ID ED IN THE CO NT RAC T BET W EEN THE T OW N OF T HE B L U E MO U NTAINS A N D TAT HAM E NGI N E E RING LT D NOR MAY A N Y D E TAIL OR E L EMENT O F TH IS D RAWI N G B E R EMOV E D, R E P RODUCE D EL ECTR ONICALLY ST OR ED O R T RA N SM ITT E D IN ANY FO R M WIT H OUT TH E E X PRE SS W RITTE N CO NSEN T OF THE T OW N OF THE BLU E MOU NTA INS NOTE: No. REVISION DES CRIPTION DATE ENG IN EERS STAM P TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRA INAGE MASTER PLAN (60% S UBM ISS ION) SE PT 2022 ALTERNATIVE SOLUTIONS MAP DES IGN: JM FILE: 121076 DWG: 7HDRAWN: KKS DATE: JU L. 2022 CHECK· DRT SCALE 1:50 00 9.1 WATERCOURSE 55 9.1.1 Project No. 1 (Culvert 198 – Sunset Boulevard) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Sunset Boulevard is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2300 mm x 1500 mm CSPA) has a capacity of approximately 5.7 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 198 would be replaced with a 3600 mm x 2100 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 55 from approximately 10 m upstream of the culvert crossing, to the watercourse outlet at Georgian Bay approximately 60 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 14.0 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 1 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 1 is recommended for inclusion in the preferred solution. As part of this project, it is recommended the Town acquire lands or interests therein (easement) encompassing and adjacent to Watercourse 55 from Sunset Boulevard to the watercourse outlet at Georgian Bay. It is recommended the Town acquire portions of 119 Sunset Boulevard and 123 Sunset Boulevard or acquire easements over portions of these properties. The proposed project is a Schedule B project. The culvert improvement is located on Watercourse 55 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 55. 9.1.2 Project No. 2 (Culvert 199 – Christie Beach Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Christie Beach Road is a collector road and therefore has a 1:50-year design flood frequency. The existing culvert crossing (1500 mm CSP) has a capacity of approximately 5.0 m3/s which corresponds to a 1:2- year design flood frequency. Project No. 2A In accordance with Scenario A as described in Section 8.3.2, Culvert 199 would be replaced with a 3300 mm x 2100 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 55 from approximately 10 m upstream of the culvert crossing, to approximately 30 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 12.9 m3/s, a design flood frequency of 1:50-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 2E In accordance with Scenario E as described in Section 8.3.2, Culvert 199 would be replaced with a 3000 mm x 1500 mm box culvert embedded 300 mm with natural substrate. This culvert improvement would not require watercourse improvements. The proposed culvert will have a capacity of 8.8 m3/s and a design flood frequency of 1:10-years (less than Town standards). However, the safe access/egress criteria for flow overtopping the road would not be satisfied under this scenario. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 2A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 2A is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 55 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 55. 9.1.3 Project No. 3 (Culvert 200 – 357516 Christie Beach Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the entrance. Entrances have a 1:5-year design flood frequency. The existing culvert crossing (1500 mm CSP) has a capacity of approximately 3.2 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 3A In accordance with Scenario A as described in Section 8.3.2, Culvert 200 would be replaced with a 2230 mm x 1700 mm CSPA culvert embedded 300 mm with natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of 7.0 m3/s and a design flood frequency of 1:5-years (satisfying Town standards). However, the crossing would not satisfy the safe access/egress criteria for flow overtopping the entrance. Project No. 3B In accordance with Scenario B as described in Section 8.3.2, Culvert 200 would be replaced with a 2800 mm x 1950 mm CSPA culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency and safe access/egress criteria. The proposed culvert would have a capacity of approximately 8.8 m3/s, a design flood frequency of 1:10-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 3B will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 3B is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A+ project. The culvert improvement is located on Watercourse 55 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review wil l satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 55. It is noted that the property whose entrance is impacted by this project (357516 Christie Beach Road) is located within the Municipality of Meaford. Therefore, the Town may wish to pursue a cost-sharing arrangement with the Municipality of Meaford for implementation of this project. 9.1.4 Project No. 4 (Culvert 201 – 357508 Christie Beach Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the entrance. Entrances have a 1:5-year design flood frequency. The existing culvert crossing (1500 mm CSP) has a capacity of approximately 4.8 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 4A In accordance with Scenario A as described in Section 8.3.2, Culvert 201 would be replaced with a 2230 mm x 1700 mm CSPA culvert embedded 300 mm with natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 7.0 m3/s and a design flood frequency of 1:5-years (satisfying Town standards). However, the crossing would not meet the safe access/egress criteria for flow overtopping the entrance. Project No. 4B In accordance with Scenario B as described in Section 8.3.2, Culvert 201 would be replaced with a 2500 mm x 1830 mm CSPA culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency and safe access/egress criteria. The proposed culvert would have a capacity of approximately 8.3 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 4B will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 4B is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A+ project. The culvert improvement is located on Watercourse 55 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 55. It is noted that the property whose entrance is impacted by this project (357508 Christie Beach Road) is located within the Municipality of Meaford. Therefore, the Town may wish to pursue a cost-sharing arrangement with the Municipality of Meaford for implementation of this project. 9.1.5 Project No. 5 (Culvert 203 – Christie Beach Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Christie Beach Road is a collector road and therefore has a 1:50-year design flood frequency. The existing culvert crossing (2-900 mm HDPE) has a capacity of approximately 2.6 m3/s which corresponds to a 1:2- year design flood frequency. Project No. 5A In accordance with Scenario A as described in Section 8.3.2, Culvert 203 would be replaced with a 2400 mm x 1800 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 55 from approximately 10 m upstream of the culvert crossing, to approximately 20 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 10.0 m3/s, a design flood frequency of 1:50-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 5E In accordance with Scenario E as described in Section 8.3.2, Culvert 203 would be replaced with an 1880 mm x 1260 mm CSPA culvert embedded 300 mm with natural substrate. This culvert improvement would not require watercourse improvements. The proposed culvert would have a capacity of approximately 7.2 m3/s and a design flood frequency of 1:10-years (less than Town standards). However, the safe access/egress criteria for flow overtopping the road would not be satisfied under this scenario. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 5A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 5A is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 55 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 55. 9.2 BOULDER CHANNEL (WATERCOURSE 56) 9.2.1 Project No. 6 (Culvert 185 – Sunset Boulevard) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Sunset Boulevard is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2000 mm x 1500 mm CSPA) has a capacity of approximately 5.7 m 3/s which corresponds to a 1:10-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 185 would be replaced with 2 – 2010 mm x 1530 mm CSPA culverts to satisfy the design flood frequency criteria. To accommodate these proposed culverts, it is required to improve Watercourse 56 from approximately 10 m upstream of the culvert crossing, to approximately 10 m downstream of the culvert crossing. The proposed culverts would have a capacity of approximately 11.5 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 6 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 6 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance and Town owned property. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Boulder Channel within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Boulder Channel. 9.2.2 Project No. 7 (Trunk Storm Sewer Improvement No. 1 – East Ridge Drive) The existing conditions analysis completed as part of this Drainage Master Plan determined there is an overland flow deficiency at East Ridge Drive. The deficiency occurs at a low point in the road where there is no overland flow route for major storm peak flows resulting in water ponding to excessive depths at this location. Project No. 7A There is an opportunity to resolve the existing overland flow deficiency described above by replacing the existing storm sewer along East Ridge Drive with a trunk storm sewer. The proposed trunk storm sewer would be sized to convey the 1:100-year peak flow. The proposed trunk sewer would consist of approximately 40 m of 750 mm storm sewer, 60 m of 825 mm storm sewer, 160 m of 900 mm storm sewer and 525 m of 1200 mm storm sewer and would discharge to Boulder Channel at the same location as the existing storm sewer. Project No. 7B There is an opportunity to resolve the existing overland flow deficiency described above by constructing a new relief storm sewer to convey major storm peak flows from the existing storm sewer along East Ridge Drive north across private properties to an outlet to Georgian Bay at Lake Drive. The proposed storm sewer would consist of approximately 130 m of 750 mm storm sewer and would convey flows across existing residential lands and golf course lands to an existing drainage feature which outlets to Georgian Bay via an existing 1400 mm CSP culvert crossing Lake Drive. As part of this project, it would be required to obtain easements over portions of 147 and 149 East Ridge Drive and a portion of the Lora Bay Golf Course to construct the proposed storm sewer. Project No. 7F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternatives under Project No. 7A and 7B. This project would involve maintaining the existing storm sewer system in East Ridge Drive. Evaluation The individual project evaluation completed for the three options developed demonstrates that Project No. 7F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 7F is recommended for inclusion in the preferred solution. As project No. 7F is the “Do Nothing” alternative, no further consideration needs to be given to Project 7. 9.3 LITTLE BEAVER RIVER 9.3.1 Project No. 8 (Culvert 176 – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (2 – 900 mm CSPs) has a capacity of approximately 2.4 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 176 would be replaced w ith a 3000 mm x 900 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 5.4 m 3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 8 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 8 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned property. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Little Beaver River within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Little Beaver River. 9.3.2 Project No. 9 (Culvert 178 – Alice Street West) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Alice Street West is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (800 mm CSP) has a capacity of approximately 0.9 m3/s which corresponds to a 1:5-year design flood frequency. Project No. 9A Under this project, Culvert 178 would be replaced with 2 – 1150 mm x 820 mm CSPA culverts. The proposed culverts would have a capacity of approximately 2.1 m3/s, a design flood frequency of 1:100-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. It is noted this culvert improvement is designed with a 1:100-year design flood frequency to match the capacity of the culverts proposed upstream at Alfred Street West and Baring Street (Projects No. 11 and 10, respectively). It is also noted that this project has the potential to increase flooding at 210 Alice Street West immediately downstream of the proposed culvert crossing due to the limited capacity of the existing culvert crossing private property. Project No. 9G In accordance with Scenario G as described in Section 8.3.2, Culvert 178 would be replaced with 2 – 1150 mm x 820 mm CSPA culverts. The proposed culvert would have a capacity of approximately 2.1 m3/s, a design flood frequency of 1:100-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. This project would also include replacement of the existing culvert located on private property at 210 Alice Street West with 2 - 1150 mm x 820 mm CSPA culverts to provide the same capacity as the proposed culvert crossing Alice Street West. Alternatively, the existing culvert located on private property at 210 Alice Street West could be removed and replaced with an open channel. Project No. 9F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternatives under Project No. 9. This project would involve maintaining existing Culvert 178 to prevent potential negative impacts on flooding downstream. Evaluation The individual project evaluation completed for the three options developed demonstrates that Project No. 9G will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 9G is recommended for inclusion in the preferred solution on the condition that permission can be obtained from the owner of 210 Alice Street West to improve or remove the existing culvert on private property. If the Town is unable to obtain the permission required to implement Project No. 9G, then Project No. 9F is recommended. The proposed culvert improvement does not require property acquisition. However, permission is required from the owner of 210 Alice Street west to complete work on private property. The proposed culvert improvements are a Schedule B project. The culvert improvement is located on the Little Beaver River within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Little Beaver River. 9.3.3 Project No. 10 (Culvert 179 – Baring Street) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Baring Street is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (700 mm x 400 mm box culvert) has a capacity of approximately 0.6 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 10A Under this project, Culvert 179 would be replaced with 2 – 1150 mm x 820 mm CSPA culverts. The proposed culverts would have a capacity of approximately 2.0 m 3/s, a design flood frequency of 1:100-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. It is noted this culvert improvement is designed with a 1:100-year design flood frequency to match the capacity of the culverts proposed upstream at Alfred Street West (Project No. 11). Project No. 10F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 10A. This project would involve maintaining the existing Culvert 179 in order to prevent potential downstream impacts due to an increase in culvert capacity. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 10A will have the greatest overall positive impact on the projec t environments and will be most beneficial to the watershed. As such Project No. 10A is recommended for inclusion in the preferred solution on the condition that the Town is able to obtain the required permission from the owner of 210 Alice Street to implement Project No. 9G downstream. If the Town is unable to obtain the permission required to implement Project No. 9G, then Project No. 10F is recommended. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Little Beaver River within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Little Beaver River. 9.3.4 Project No. 11 (Culvert 180 Improvement – Alfred Street West) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Alfred Street West is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (700 mm HDPE) has a capacity of approximately 0.4 m3/s which corresponds to a 1:2- year design flood frequency. Project No. 11A In accordance with Scenario A as described in Section 8.3.2, Culvert 180 would be replaced with 2 – 1150 mm x 820 mm CSPA culverts to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 2.0 m3/s, a design flood frequency of 1:100- years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 11F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 11A. This project would involve maintaining the existing Culvert 180 in order to prevent potential downstream impacts due to an increase in culvert capacity. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 11A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 11A is recommended for inclusion in the preferred solution on the condition that the Town is able to obtain the required permission from the owner of 210 Alice Street to implement Project No. 9G downstream. If the Town is unable to obtain the permission required to implement Project No. 9G, then Project No. 11F is recommended. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Little Beaver River within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Little Beaver River. 9.3.5 Project No. 12 (Bridge 171 – Alice Street West) The existing conditions analysis completed as part of this Drainage Master Plan determined that this bridge crossing does not satisfy the Town design flood frequency criteria. Alfred Street West is a local road and therefore has a 1:25-year design flood frequency. The existing bridge crossing (6.2 m span) has a capacity of approximately 45.8 m3/s which corresponds to a 1:10-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Bridge 171 would be replaced with an 8.2 m span bridge to satisfy the design flood frequency criteria. The proposed bridge would have a capacity of approximately 65.7 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 12 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 12 is recommended for inclusion in the preferred solution. The proposed bridge improvement does not require property acquisition as the works can be completed within the road allowance. The proposed bridge improvement is a Schedule A project. The culvert improvement is located on Little Beaver River within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Little Beaver River. 9.3.6 Project No. 13 (Culvert 173 – Napier Street West) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Napier Street West is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2000 mm CSP) has a capacity of approximately 9.4 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 173 would be replaced with a 4800 mm x 2100 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve the Little Beaver River from approximately 6 m upstream of the culvert crossing, to approximately 6 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 24.9 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 13 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 13 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Little Beaver River within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Little Beaver River. 9.3.7 Project No. 14 (Culvert 174 – Duncan Street West) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Duncan Street West is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2000 mm CSP) has a capacity of approximately 10.2 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 174 would be replaced with a 4800 mm x 2100 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve the Little Beaver River from approximately 5 m upstream of the culvert crossing, to approximately 5 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 24.7 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 14 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 14 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Little Beaver River within the GSCA Regulated Ar ea and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Little Beaver River. 9.3.8 Project No. 113 (Culvert 175 – Alfred Street West) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Alfred Street West is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (3600 mm x 1400 mm box) has a capacity of approximately 14.8 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 175 would be replaced with an 8.2 m open bottom span structure to satisfy the design flood frequency criteria. To accommodate this proposed span structure, it is required to improve the Little Beaver River from approximately 5 m upstream of the culvert crossing, to approximately 5 m downstream of the culvert crossing. The proposed span structure would have a capacity of approximately 50.6 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 113 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 113 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acqu isition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Little Beaver River within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Little Beaver River. 9.4 ELGIN STREET NORTH 9.4.1 Project No. 15 (Trunk Storm Sewer Improvement No. 2 – King Street East) The existing conditions analysis completed as part of this Drainage Master Plan determined there is an overland flow deficiency on King Street East. The deficiency occurs at a low point in the road where there is no overland flow route for major storm peak flows resulting in water ponding to excessive depths at this location. Project No. 15A There is an opportunity to resolve the existing overland flow deficiency described above by replacing the existing storm sewer in King Street East and Elgin Street North with a trunk storm sewer. The proposed trunk storm sewer has been sized to convey the 1:100-year peak flow. The proposed trunk sewer would consist of approximately 45 m of 600 mm sewer, 50 m of 675 m sewer, 45 m of 900 mm sewer and 385 m of 1050 mm sewer and would discharge to Georgian Bay at the north end of Elgin Street North at the same location as the existing storm sewer. Project No. 15F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 15A. This project would involve maintaining the existing storm sewer system along King Street East and Elgin Street North. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 15A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 15A is recommended for inclusion in the preferred solution. The proposed trunk storm sewer improvement does not require property acquisition as the works can be completed within the road allowance. The proposed improvement is a Schedule A project. The improvement is located on King Street East and Elgin Street North . The sewer outlet is located within the GSCA Regulated Area and therefore the works will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. 9.5 BEAVER RIVER 9.5.1 Project No. 17 (Storm Sewer Relocation – Clarksburg) The existing conditions analysis completed as part of this Drainage Master Plan identified approximately 175 m of storm sewer in Clarksburg which conveys municipal drainage but is located on private property. This storm sewer is located on 165 and 173 Clark Street, 183 and 185 Marsh Street, and 108 George Street and conveys drainage from the municipal storm sewer located in Marsh Street. The sewer runs under the building located at 165 Clark Street and is believed to also receive flows from an undocumented drainage system which was previously the historical Clarksburg mill flume at this location. The existing sewer discharges to the Beaver River northeast of the intersection of Mary Street and George Street. Project No. 17A There is an opportunity to relocate the storm sewer described above out of private property an d into the municipal road allowance. Under this project, a new 750 mm storm sewer would be installed in Clark Street and Mary Street and would convey discharge from the Marsh Street storm sewer to the existing outlet of the undocumented drainage system described above. Additionally, the existing storm sewer located on private property would be decommissioned and abandoned in place. It is recommended that a thorough field investigation be conducted at the onset of this project to better understand the extents of the existing undocumented drainage system and its relationship to the local storm drainage system. Project No. 17F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 17A. This project would involve maintaining the existing undocumented drainage system on private property. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 17A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 1 7A is recommended for inclusion in the preferred solution. The proposed storm sewer improvement does not require property acquisition as the proposed works involve decommissioning drainage systems on private property and the proposed infrastructure will be relocated within the municipal road allowance. However, consultation with the owners of the properties affected by the proposed works is required. The proposed improvement is a Schedule B project. The improvement is located on Clark Street and Mary Street. The improvement project is located within the GSCA Regulated Area and therefore the works will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Beaver River. 9.5.2 Project No. 18 (Decommission Historical Clarksburg Mill Flume – Clarksburg) The existing conditions analysis completed as part of this Drainage Master Plan identified an undocumented drainage system which is partially located on private property. This drainage system is believed to be the remnants of the historical Clarksburg mill flume. The drainage system is believed to originate at 174 Marsh Street, continue along Marsh Street where it is believed to receive flows from storm sewers located on Marsh Street and Clark Street and then join with the Marsh Street sewer beneath the building located at 165 Clark Street before discharging to the Beaver River via the existing sewer within private property described in Project No. 17. Project No. 18A There is an opportunity to decommission the undocumented drainage system described above. Under this project, the undocumented system would be decommissioned and either abandoned in place or removed from private property and the municipal road allowance (to be confirmed at detailed design). Thorough field investigation is recommended to confirm the extents of the undocumented system in order to verify the system can be removed from the affected private properties without negatively impacting the properties or any structures therein. As part of this project, the existing storm sewer on Clark Street west of Marsh Street and the existing storm sewer on Marsh Street north of Clark Street will be replaced and connected to the storm sewer proposed on Clark Street under Project No. 17. Project No. 18F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 18A. This project would involve maintaining the existing undocumented drainage system. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 18A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 1 8A is recommended for inclusion in the preferred solution. The proposed project does not require property acquisition as the proposed works involve decommissioning drainage systems on private property and the proposed infrastructure will be located within the road allowance. However, consultation with the owners of the properties affected by the proposed works is required. The proposed improvement is a Schedule B project. The improvement is located on Clark Street and Mary Street. The improvement project is located within the GSCA Regulated Area and therefore the works will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of the Beaver River. 9.6 WATERCOURSE 42 9.6.1 Project No. 19 (Culvert 158 – Bayview Avenue) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Bayview A venue is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2 – 600 mm CSPs) has a capacity of approximately 1.0 m3/s which corresponds to a 1:10-year design flood frequency. Project No. 19A In accordance with Scenario A as described in Section 8.3.2, Culvert 158 would be replaced with a 1630 mm x 1120 mm CSPA culvert to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 42 from approximately 20 m upstream of the culvert crossing, to the watercourse outlet at Georgian Bay approximately 110 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 2.4 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 19F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 19. This project would involve maintaining existing Culvert 158. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 19F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 19F is recommended for inclusion in the preferred solution. As project No. 19F is the “Do Nothing” alternative, no further consideration needs to be given to Project 19. 9.7 WATERCOURSE 52 9.7.1 Project No. 20 (Culvert 147 – Lakeshore Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing satisfies the Town design flood frequency criteria but does not satisfy the recommended safe access/egress criteria for flow overtopping the road. Bayview Avenue is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2400 mm x 800 mm box) has a capacity of approximately 5.3 m3/s which corresponds to a 1:25- year design flood frequency. Project No. 20G In accordance with Scenario G as described in Section 8.3.2, Culvert 147 would be replaced with a 4500 mm x 1500 mm box culvert embedded with 300 mm of natural substrate. The proposed culvert would have a capacity of approximately 8.6 m3/s, a design flood frequency of 1:100-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. It is noted this culvert improvement is designed with a 1:100-year design flood frequency to match the capacity of the culvert improvements proposed upstream at Grey Road 2, Highway 26 and the Georgian Trail (Projects 23, 22 and 21, respectively). Project No. 20F – Do Nothing This project is considered as a baseline for comparison against the proposed im provement alternative under Project No. 20. This project would involve maintaining the existing Culvert 147 in order to prevent potential negative impacts on flooding downstream. Evaluation The individual project evaluation completed for the two options de veloped demonstrates that Project No. 20G will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 20G is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 52 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 52. 9.7.2 Project No. 21 (Culvert 148 – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing satisfies the Town design flood frequency criteria and the recommended safe access/egress criteria for flow overtopping the trail. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (1500 mm CSP) has a capacity of approximately 7.1 m3/s which corresponds to a 1:50-year design flood frequency. Project No. 21G In accordance with Scenario G as described in Section 8.3.2, Culvert 148 would be replaced with a 4500 mm x 1500 mm box culvert embedded with 300 mm of natural substrate. The proposed culvert would have a capacity of approximately 13.0 m3/s, a design flood frequency of 1:100- years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. It is noted this culvert improvement is designed with a 1:100-year design flood frequency to match the capacity of the culvert improvements proposed upstream at Grey Road 2 and Highway 26 (Projects 23 and 22, respectively). Project No. 21F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 21. This project would involve maintaining the existing Culvert 148 in order to prevent potential negative impacts on flooding downstream. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 21G will have the greatest overall positive impact on the proj ect environments and will be most beneficial to the watershed. As such Project No. 21G is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 52 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 52. 9.7.3 Project No. 22 (Culvert 149 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing satisfies the MTO design flood frequency criteria and the recommended safe access/egress criteria for flow overtopping the road. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (1800 mm x 1100 mm CSPA) has a capacity of approximately 5.5 m3/s which corresponds to a 1:25-year design flood frequency. Project No. 22G In accordance with Scenario G as described in Section 8.3.2, Culvert 149 would be replaced with a 4500 mm x 1500 mm box culvert embedded with 300 mm of natural substrate. To accommodate this proposed culvert, it is required to improve Watercourse 52 from approximately 10 m upstream of the culvert crossing, to approximately 6 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 12.5 m3/s, a design flood frequency of 1:100-years (exceeding MTO standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. It is noted this culvert improvement is designed with a 1:100-year design flood frequency to match the capacity of the culvert improvements proposed upstream at Grey Road 2 (Project 23). Project No. 22F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 22. This project would involve maintaining the existing Culvert 149 in order to prevent potential negative impacts on flooding downstream. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 22G will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 22G is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 52 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 52. 9.7.4 Project No. 23 (Culvert 150 – Grey Road 2) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Grey Road 2 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (1700 mm x 1300 mm CSPA) has a capacity of approximately 3.6 m 3/s which corresponds to a 1:5-year design flood frequency. Project No. 23A In accordance with Scenario A as described in Section 8.3.2, Culvert 150 would be replaced with a 4500 mm x 1500 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 52 from approximately 15 m upstream of the culvert crossing, to approximately 10 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 8.5 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 23E In accordance with Scenario E as described in Section 8.3.2, Culvert 150 would be replaced with 2 – 2010 mm x 1530 mm CSPA culverts embedded 300 mm with natural substrate. This culvert replacement would not require watercourse improvements. The proposed culvert would have a capacity of approximately 8.0 m3/s and a design flood frequency of 1:50-years (less than Town standards). However, the safe access/egress criteria for flow overtopping the road would not be satisfied under this scenario. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 23A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 23A is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 52 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satis fy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 52. 9.7.5 Project No. 24 (Culvert 156 – Clark Street) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Clark Street is a collector road and therefore has a 1:50-year design flood frequency. The existing culvert crossing (600 mm CSP) has a capacity of approximately 0.3 m3/s which corresponds to a less than 1:2- year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 156 would be replaced with a 3300 mm x 1200 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 52 from approximately 50 m upstream of the culvert crossing, to approximately 40 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 4.8 m3/s, a design flood frequency of 1:50-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 24 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 24 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition , however permission is required from the owner of the property known as CON 8 AND 9 PT LOT 31 as the proposed works will extend onto private property. The proposed culvert improvement is a Schedule A+ project. The culvert improvement is located on Watercourse 52 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 52. 9.7.6 Project No. 25 (Culvert 151 – 496916 Grey Road 2) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the entrance. Entrances have a 1:5-year design flood frequency. The existing culvert crossing (600 mm CSP) has a capacity of approximately 0.5 m3/s which corresponds to a less than 1:2-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 151 would be replaced with 2 – 800 mm CSP culverts to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 52 from approximately 12 m upstream of the culvert crossing, to approximately 25 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 1.6 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the entrance when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 25 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 25 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 52 within the GSCA Regulated Area and will require a permit from the GSCA. 9.7.7 Project No. 26 (Culvert 152 – Unopened Road Allowance at Grey Road 2) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the entrance. Entrances have a 1:5-year design flood frequency. The existing culvert crossing (450 mm CSP) has a capacity of approximately 0.2 m3/s which corresponds to a less than 1:2-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 152 would be replaced with 2 – 800 mm CSP culverts to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 52 from approximately 10 m upstream of the culvert crossing, to approximately 60 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 1.5 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the entrance when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 26 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 26 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 52 within the GSCA Regulated Area and will require a permit from the GSCA. 9.8 WATERCOURSE 41 9.8.1 Project No. 27 (Culvert 145 – Lakeshore Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing provides less capacity than the culvert crossing Highway 26 immediately upstream (Culvert 146). The existing Culvert 145 (2700 mm x 1100 mm box culvert) has a capacity of approximately 5.7 m3/s while the existing Culvert 146 (2400 mm x 2100 mm box culvert) upstream has a capacity to convey approximately 18.0 m3/s before flow will spill over the Georgian Trail and back into Indian Brook upstream of Highway 26. Although the existing Culvert 145 does not have a capacity near to that of Culvert 146 upstream, the existing Culvert 145 crossing does satisfy the safe access/egress criteria for flow overtopping the road. Project No. 27G In accordance with Scenario G as described in Section 8.3.2, Culvert 145 would be replaced with a 6000 mm x 1800 mm concrete box culvert embedded with 300 mm of natural substrate. The proposed culvert would have a capacity of approximately 14.5 m3/s, which is approaching the capacity of Culvert 146 upstream and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. This proposed culvert would reduce the maximum depth of overtopping to 0.10 m under a flow of 18.0 m3/s. Project No. 27E In accordance with Scenario E as described in Section 8.3.2, Culvert 145 would be replaced with a 4200 mm x 1500 mm concrete box culvert embedded with 300 mm of natural substrate. The proposed culvert would have a capacity of approximately 8.0 m3/s and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. This proposed culvert would reduce the maximum depth of overtopping to 0.17 m under a flow of 18.0 m3/s. Project No. 27F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 27G. This project would involve maintaining the existing Culvert 145. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 27F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 27F is recommended for inclusion in the preferred solution. As project No. 27F is the “Do Nothing” alternative, no further consideration needs to be given to Project 27. 9.8.2 Project No. 118 – Reduce Capacity of Culvert 146 The existing conditions analysis completed as part of this Drainage Master Plan determined that the culvert crossing downstream of Culvert 146 (Culvert 145) has significantly less capacity than Culvert 146. There is a potential for Culvert 146 to convey pe ak flows up to 17.0 m3/s during a significant storm where flow spills from Indian Brook to Culvert 146, while existing Culvert 145 only has a capacity of approximately 5.7 m3/s. Although existing Culvert 145 does not have sufficient capacity to convey the peak flow of 17.0 m3/s, the culvert crossing does satisfy the recommended safe access/egress criteria for flow overtopping the road. Project No. 118A Under this project, the capacity of the culvert crossing Highway 26 will be reduced to a maximum of approximately 11.5 m3/s. This value was determined as the peak flow which can be conveyed by the existing Culvert 145 culvert crossing at a maximum overtopping depth of 0.15 m. The capacity of the Culvert 146 culvert crossing would be reduced by forming a concrete barrier at the culvert inlet to reduce the effective culvert flow area, or a similar alternative method. Project No. 118F – Do Nothing This project is considered as a baseline for comparison against the proposed improveme nt alternative under Project No. 118A This project would involve maintaining existing Culvert 146. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 118F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 118F is recommended for inclusion in the preferred solution. As project No. 118F is the “Do Nothing” alternative, no further consideration needs to be given to Project 118. 9.9 WATERCOURSE 34 9.9.1 Project No. 28 (Culvert 135 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the MTO design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (3660 mm x 1830 mm box culvert) has a capacity of approximately 17.0 m3/s which corresponds to a 1:5-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 135 would be replaced with a 4800 mm x 2100 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 22.1 m3/s, a design flood frequency of 1:25-years (satisfying MTO standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. As part of this project, Watercourse 34 will be improved from the culvert crossing approximately 65 m downstream to the watercourse outlet to Georgian Bay. Evaluation The individual project evaluation demonstrates that Project No. 28 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 28 is recommended for inclusion in the preferred solution. As part of this project, it is recommended the Town acquire the portion of 208653 Highway 26 that Watercourse 34 passes through. The proposed culvert improvement is a Schedule B project. The culvert improvement is located on Watercourse 34 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 34. 9.9.2 Project No. 29 (Culvert 135A – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the MTO design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (1600 mm x 1200 mm CSPA) has a capacity of approximately 5.4 m 3/s which corresponds to a 1:5-year design flood frequency. Project No. 29A Under this project, Culvert 135A would be replaced with a 3300 mm x 2080 mm CSPA culvert embedded with 300 mm of natural substrate. To accommodate the proposed culvert, the watercourse will be improved from the culvert crossing to approximately 50 m downstream to the watercourse outlet to Georgian Bay. The proposed culvert would have a capacity of approximately 16.5 m3/s, a design flood frequency of 1:25-years (satisfying MTO standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 29F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 29A. This project would involve maintaining the existing Culvert 135A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 29A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 29A is recommended for inclusion in the preferred solution. The proposed culvert improvement requires acquisition of easements over a portion of 208655 Highway 26 and 208663 Highway 26 to accommodate the proposed watercourse improvements downstream of the culvert. The proposed culvert improvement is a Schedule B project. The culvert improvement is located on Watercourse 34 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 34. 9.9.3 Project No. 30 (Culvert 136 – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria or the recommended safe access/egress criteria for flow overtopping the trail. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (3900 mm x 2850 mm CSPA) has a capacity of approximately 14.0 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 136 would be replaced with a 4800 mm x 2100 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 23.0 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 30 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 30 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 34 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 34. 9.9.4 Project No. 31 (Culvert 137 – Indian Circle) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria or the recommended safe access/egress criteria for flow overtopping the road. Indian Circle is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2 - 2400 mm x 1500 mm box culverts) has a capacity of approximately 19.2 m3/s which corresponds to a 1:5-year design flood frequency. Project No. 31A In accordance with Scenario A as described in Section 8.3.2, Culvert 137 would be replaced with 2 – 6000 mm x 1800 mm box culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. Also, as part of this project, Watercourse 34 would be significantly improved from approximately 30 m upstream of the culvert crossing to approximately 75 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 35.0 m3/s and a design flood frequency of 1:25-years satisfying Town standards). However, the culvert crossing would not satisfy the safe access/egress criteria for flow overtopping the road when unobstructed but would significantly reduce the depth of water flowing over the road during the Regulatory Storm. Project No. 31E In accordance with Scenario E as described in Section 8.3.2, Culvert 137 would be replaced with 2 – 4200 mm x 1800 mm box culverts embedded with 300 mm of natural substrate. Also as part of this project, Watercourse 34 would be improved from approximately 30 m upstream of the culvert crossing to approximately 75 m downstream of the culvert crossing. This proposed culvert would be less expensive than the culvert proposed under Project No. 31A, and would provide a similar, albeit lower, level of service. The proposed culvert would have a capacity of approximately 28.1 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would not meet the safe access/egress criteria for flow overtopping the road when unobstructed but would significantly reduce the depth of water flowing over the road during the Regulatory storm. Project No. 31F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternatives under Projects No. 31A and 31E. This project would involve maintaining the existing Culvert 137. Evaluation The individual project evaluation completed for the three options developed demonstrates that Project No. 31E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 31E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance and Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 34 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 34. 9.9.5 Project No. 32 (Culvert 138 – 7th Line) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria or the recommended safe access/egress criteria for flow overtopping the road. 7th Line is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (3000 mm CSP embedded 500 mm) has a capacity of approximately 19.0 m3/s which corresponds to a 1:5- year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 138 would be replaced with a 6000 mm x 1800 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 34.0 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 32 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 32 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 34 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 34. 9.9.6 Project No. 33 (Floodplain Storage Expansion No. 16 – 7th Line) There is an opportunity to expand the existing floodplain storage area upstream of the culvert crossing 7th Line (Culvert 138) to provide additional peak flow attenuation for major storms and reduce flooding downstream. Project No. 33A As part of this project, approximately 1.0 ha of area upstream of Culvert 138 would be cleared, excavated, and graded to create approximately 5,000 m3 of additional floodplain storage volume upstream of the culvert crossing. The existing watercourse banks would be maintained, and the floodplain storage area would only be engaged during significant flow events exceeding the capacity of the low flow channel. It is noted this project would require property acquisition of a portion of CON 8 SE PT LOT 27 to accommodate the proposed works. The VO major system hydrologic model was updated to include proposed Floodplain Storage Expansion No. 16 to assess the impact of the project on the design storm peak flows. It was determined that this project would have a minimal impact on peak flows downstream in Watercourse 34 with the 1:25-year design storm peak flow being reduced by approximately 2%. Project No. 33F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 33A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 33F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 33F is recommended for inclusion in the preferred solution. As project No. 33F is the “Do Nothing” alternative, no further consideration needs to be given to Project 33. 9.10 WATERCOURSE 32 9.10.1 Project No. 34 (Watercourse Improvement – Watercourse 32) The existing conditions analysis identified a flooding concern for the two properties adjacent to the most downstream section of Watercourse 32 (133 & 135 Hoover Lane). The existing residences at these properties are at risk of flooding during the Timmins Storm. There is an opportunity to acquire one of the two properties at risk and improve the downstream section of Watercourse 32 to increase its conveyance capacity. Project No. 34A As part of this project, approximately 100 m of Watercourse 32 would be improved, and a floodway would be graded adjacent to the watercourse to improve conveyance capacity and reduce the elevation of flood flows in this section of the watercourse. To accommodate the proposed improvement, it is required to purchase 135 Hoover Lane and demolish the existing structure on this property. The proposed improvements would reduce flood levels during the Timmins storm such that they are contained within the channel and floodway and the risk to the remaining residence at 133 Hoover Lane would be eliminated. Project No. 34F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 34A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 34A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 34A is recommended for inclusion in the preferred solution. The proposed watercourse improvement requires acquisition of 135 Hoover Lane. The proposed improvement project is a Schedule B project. The project is located on Watercourse 32 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 32. 9.10.2 Project No. 35 (Culvert 130 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the MTO design flood frequency criteria. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (3050 mm x 1830 mm box culvert) has a capacity of approximately 16.2 m3/s which corresponds to a 1:10-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 130 would be replaced with a 3900 mm x 2100 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 22.3 m3/s, a design flood frequency of 1:25-years (satisfying MTO standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 35 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 35 is recommended for inclusion in the preferred solution on the condition the Town is able to complete Project No. 34A downstream. If the Town is unable to complete Project 34A, then Project No. 35 is not recommended. The proposed culvert improvement does not require property acqu isition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 32 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 32. 9.10.3 Project No. 36 (Culvert 132 – Stone Zack Lane) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency crit eria. Stone Zack Lane is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2 – 900 mm CSPs) has a capacity of approximately 2.6 m3/s which corresponds to a 1:10-year design flood frequency. Project No. 36A In accordance with Scenario A described in Section 8.3.2, Culvert 132 would be replaced with 2 – 1000 mm CSP culverts to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 3.6 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 36F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 36A. This project would involve maintaining the existing Culvert 132. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 36F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 36F is recommended for inclusion in the preferred solution. As project No. 36F is the “Do Nothing” alternative, no further consideration needs to be given to Project 36. 9.10.4 Project No. 37 (Culvert 134 – George McRae Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. George McRae Road is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (3 – 910 mm x 660 mm CSPAs) has a capacity of approximately 2.4 m3/s which corresponds to a 1:10-year design flood frequency. Project No. 37A In accordance with Scenario A described in Section 8.3.2, Culvert 134 would be replaced with 3 – 910 mm x 660 mm CSPA culverts at lower invert elevation and Watercourse 32 would be improved from approximately 10 m upstream of the culvert crossing to approximately 10 m downstream of the culvert crossing to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 3.6 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 37F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 37A. This project would involve maintaining the existing Culvert 134. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 37F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 37F is recommended for inclusion in the preferred solution. As project No. 37F is the “Do Nothing” alternative, no further consideration needs to be given to Project 37. 9.11 WATERCOURSE 31 9.11.1 Project No. 38 (Culvert 124 – Hoover Lane) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Hoover Lane is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2 – 800 mm CSPs) has a capacity of approximately 0.6 m3/s which corresponds to a less than 1:2-year design flood frequency. Project No. 38A In accordance with Scenario A as described in Section 8.3.2, Culvert 124 would be replaced with a 6000 mm x 1200 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to widen and improve Watercourse 31 from approximately 15 m upstream of the culvert crossing, to the watercourse outlet at Georgian Bay approximately 35 m downstream of the culvert crossing. The proposed watercourse widening would have a significant impact on the extension of Camperdown Road which provides access to Georgian Bay. The proposed culvert would have a capacity of approximately 12.5 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 38E In accordance with Scenario E as described in Section 8.3.2, Culvert 124 would be replaced with a 4500 mm 1200 mm box culvert embedded 300 mm with natural substrate. To accommodate this proposed culvert, it is required to widen and improve Watercourse 31 from approximately 15 m upstream of the culvert crossing, to the watercourse outlet at Georgian Bay approximately 35 m downstream of the culvert crossing. The proposed watercourse widening would have an impact, albeit less of an impact than Project 38A, on the extension of Camperdown Road which provides access to Georgian Bay. The proposed culvert would have a capacity of approximately 10.2 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 38E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 38E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 31 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 31. 9.11.2 Project No. 39 (Culvert 125 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does satisfy the MTO design flood frequency criteria and the recommended safe access/egress criteria for flow overtopping the road. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (3050 mm x 1220 mm box culvert) has a capacity of approximately 12.0 m3/s which corresponds to a 1:25-year design flood frequency. However, under future conditions, the culvert does not satisfy the Town design flood frequency criteria. Project No. 39A Under this project, Culvert 125 would be replaced with a 3600 mm x 1500 mm box culvert embedded with 300 mm of natural substrate. The proposed culvert would have a capacity of approximately 12.5 m3/s, a design flood frequency of 1:25-years (satisfying MTO standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 39F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 39A. This project would involve maintaining the existing Culvert 125. Evaluation The individual project evaluation completed for th e two options developed demonstrates that Project No. 39F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 39F is recommended for inclusion in the preferred solution. As project No. 39F is the “Do Nothing” alternative, no further consideration needs to be given to Project 39. 9.11.3 Project No. 40 (Culvert 128 – George McRae Road) The existing conditions analysis completed as part of this Drainage Master Plan determined tha t this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. George McRae Road is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2 – 1200mm CSPs) has a capacity of approximately 3.0 m3/s which corresponds to a 1:5-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 128 would be replaced with 2 – 1880 mm x 1260 mm CSPA culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 5.2 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 40 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 40 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 31 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 31. 9.11.4 Project No. 41 (Trunk Storm Sewer Improvement No. 3 – Camperdown Road) The existing conditions analysis completed as part of this Drainage Master Plan determined there is an overland flow deficiency at Camperdown Road. The deficiency occurs along approximately 600 m of the road as the steep slope of the road results in overland flow velocities exceeding the maximum value specified in the Town’s standards under the 1:100-year design storm. Project No. 41A There is an opportunity to resolve the existing overland flow deficiency described above by replacing the existing storm sewer along Camperdown Road with a trunk storm sewer. The proposed trunk storm sewer would be sized to convey the 1:100-year peak flow. The proposed trunk sewer would consist of approximately 570 m of 675 mm sewer and 30 m of 750 mm sewer and would discharge to the Camperdown Road east roadside ditch at the same location as the existing storm sewer. Project No. 41F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 41A. This project would involve maintaining the existing storm sewer system in Camperdown Road. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 41F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 41F is recommended for inclusion in the preferred solution. As project No. 41F is the “Do Nothing” alternative, no further consideration needs to be given to Project 41. 9.12 OUTLET 30 9.12.1 Project No. 42 (Culvert 121 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the MTO design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Hi ghway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (800mm CSP) has a capacity of approximately 1.0 m3/s which corresponds to a less than 1:2- year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 128 would be replaced with an 1880 mm x 1260 mm CSPA culvert to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 4.0 m3/s, a design flood frequency of 1:50-years (exceeding MTO standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 42 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 42 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Outlet 30 within the GSCA Regulated Area and will require a permit from the GSCA. 9.12.2 Project No. 43 (Culvert 122 – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (750mm CSP) has a capacity of approximately 0.7 m3/s which corresponds to a less than 1:2-year design flood frequency. In accordance with Scenario G as described in Section 8.3.2, Culvert 122 would be replaced with an 1880 mm x 1260 mm CSPA culvert. The proposed culvert would have a capacity of approximately 3.3 m3/s, a design flood frequency of 1:25-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 43 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 43 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Outlet 30 within the GSCA Regulated Area and will require a permit from the GSCA. 9.12.3 Project No. 44 (Culvert 123 – Old Lakeshore Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria or the recommended safe access/egress criteria for flow overtopping the road. Old Lakeshore Road is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (1500 mm x 600 mm CSPA) has a capacity of approximately 1.2 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 123 would be replaced with an 1880 mm x 1260 mm CSPA culvert to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve the Outlet 30 watercourse from approximately 7 m upstream of the culvert crossing, to approximately 6 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 3.3 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 44 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 44 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Outlet 30 within the GSCA Regulated Area and will require a permit from the GSCA. 9.13 WATERCOURSE 28 9.13.1 Project No. 45 (Culvert 117 – Old Lakeshore Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Old Lakeshore Road is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (1100 mm x 870 mm box culvert) has a capacity of approximately 2.0 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 117 would be replaced with a 3000 mm x 900 mm box culvert to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 28 from approximately 6 m upstream of the culvert crossing, to approximately 5 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 5.6 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 45 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 45 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 28 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 28. 9.14 OUTLET 26 9.14.1 Project No. 46 (Culvert 113 – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does satisfy the Town design flood frequency criteria and the recommended safe access/egress criteria for flow overtopping the road. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (2000 mm x 1400 mm CSPA) has a capacity of approximately 5.3 m3/s which corresponds to a 1:5-year design flood frequency. However, this culvert crossing has a limiting effect on the capacity of the culvert crossing immediately upstream at Wensley Drive (Culvert 114). In accordance with Scenario G as described in Section 8.3.2, Culvert 113 would be replaced with a 3600 mm x 900 mm box culvert. The proposed culvert would have a capacity of approximately 6.3 m3/s, a design flood frequency of 1:10-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 46 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 46 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Outlet 26 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Outlet 26. 9.14.2 Project No. 47 (Culvert 114 – Wensley Drive) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (2000 mm x 1400 mm CSPA) has a capacity of approximately 5.3 m 3/s which corresponds to a 1:5-year design flood frequency. Project No. 47A In accordance with Scenario A as described in Section 8.3.2, Culvert 114 would be replaced with a 4800 mm x 1200 mm box culvert to satisfy the design flood frequency criteria. To accommodate the proposed culvert, it is required to regrade and raise the road above the proposed culvert. The proposed culvert would have a capacity of approximately 8.0 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 47E In accordance with Scenario E as described in Section 8.3.2, Culvert 114 would be replaced with a 3600 mm x 900 mm box culvert. This proposed culvert crossing does not require regrading of the road to accommodate the proposed culvert. The proposed culvert would have a capacity of approximately 6.5 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 47E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 47E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. However, it is recommended the Town purchase (or acquire an easement over) a portion of 121 Wensley Drive and CON 5 PT LOT 26 so that the Town can more easily access the watercourse for maintenance if required. The proposed culvert improvement is a Schedule B project. The culvert improvement is located on Outlet 26 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Outlet 26. 9.15 OUTLET 25 9.15.1 Project No. 48 (Culvert 108 – Delphi Lane) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Delphi Lane is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2100 mm x 900 mm box culvert) has a capacity of approximately 4.0 m 3/s which corresponds to a 1:10-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 108 would be replaced with a 3300 mm x 1200 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Outlet 25 from approximately 10 m upstream of the culvert crossing, to approximately 15 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 5.6 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 48 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 48 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property a cquisition as the works can be completed within the road allowance and Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Outlet 26 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Outlet 26. 9.15.2 Project No. 49 (Culvert 109 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does satisfy the MTO design flood frequency criteria and the recommended safe access/egress criteria for flow overtopping the road. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2500 mm x 750 mm box culvert) has a capacity of approximately 4.6 m3/s which corresponds to a 1:10-year design flood frequency. This project was considered to improve the performance of the culvert crossing immediately upstream at the Georgian Trail (Culvert 110) which was identified as deficient through the existing conditions analysis. Project No. 49A In accordance with Scenario A as described in Section 8.3.2, Culvert 109 would be replaced with a 2700 mm x 1200 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 5.6 m3/s, a design flood frequency of 1:25-years (satisfying MTO standards) and would meet the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 49F – Do Nothing This project is considered as a baseline for comparison again st the proposed improvement alternative under Project No. 49A. This project would involve maintaining the existing Culvert 109. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 49F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 49F is recommended for inclusion in the preferred solution. As project No. 49F is the “Do Nothing” alternative, no further consideration needs to be given to Project 49. 9.15.3 Project No. 50 (Culvert 110 – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (2 – 750 mm CSPs) has a capacity of approximately 2.2 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 50A In accordance with Scenario A as described in Section 8.3.2, Culvert 110 would be replaced with 2 – 1000 mm CSP culverts to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 3.3 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Project No. 50F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 50A. This project would involve maintaining the existing Culvert 110. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 50F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 50F is recommended for inclusion in the preferred solution. As project No. 50F is the “Do Nothing” alternative, no further consideration needs to be given to Project 50. 9.16 OUTLET 24 9.16.1 Project No. 51 (Culvert 107 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the MTO design flood frequency criteria. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (870 mm x 500 mm CSPA) has a capacity of approximately 0.6 m3/s which corresponds to a 1:5- year design flood frequency. Project No. 51A In accordance with Scenario A as described in Section 8.3.2, Culvert 107 would be replaced with an 1150 mm x 820 mm CSPA culvert to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 1.1 m3/s, a design flood frequency of 1:25-years (satisfying MTO standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 51F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 51A. This project would involve maintaining the existing Culvert 107. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 51F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 51F is recommended for inclusion in the preferred solution. As project No. 51F is the “Do Nothing” alternative, no further consideration needs to be given to Project 51. 9.17 OUTLET 23 9.17.1 Project No. 52 (Culvert 105 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the MTO design flood frequency criteria. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (600 mm CSP) has a capacity of approximately 0.5 m3/s which corresponds to a 1:5-year design flood frequency. In accordance with Scenario G as described in Section 8.3.2, Culvert 105 would be replaced with 2 - 600 mm diameter CSP culverts. To accommodate the proposed culverts, it is required to regrade and lower the ditch at the upstream side of the proposed culverts. The proposed culverts would have a capacity of approximately 1.3 m3/s, a design flood frequency of 1:100-years (exceeding MTO standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. This culvert crossing has been designed to exceed the MTO required design flood frequency to improve the performance of Culvert 106 immediately upstream. Evaluation The individual project evaluation demonstrates that Project No. 52 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 52 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on a roadside ditch and is not within the GSCA Regulated Area. 9.17.2 Project No. 53 (Culvert 106 – Wards Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Wards Road is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (600 mm CSP) has a capacity of approximately 0.3 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 53A In accordance with Scenario A as described in Section 8.3.2, Culvert 106 would be replaced with 2 – 600 mm CSP culverts to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 0.9 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 53F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 53A. This project would involve maintaining the existing Culvert 106. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 53F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 53F is recommended for inclusion in the preferred solution. As project No. 53F is the “Do Nothing” alternative, no further consideration needs to be given to Project 53. 9.18 WATERCOURSE 22 9.18.1 Project No. 54 (Culvert 103 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the MTO design flood frequency criteria. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (1300 mm x 800 mm CSPA) has a capacity of approximately 2.2 m3/s which corresponds to a 1:10-year design flood frequency. Project No. 54A In accordance with Scenario A as described in Section 8.3.2, Culvert 103 would be replaced with an 1880 mm x 1260 mm CSPA culvert to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 4.2 m3/s, a design flood frequency of 1:25-years (satisfying MTO standards) and would saisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 54F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 54A. This project would involve maintaining the existing Culvert 103. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 54F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 54F is recommended for inclusion in the preferred solution. As project No. 54F is the “Do Nothing” alternative, no further consideration needs to be given to Project 54. 9.18.2 Project No. 55 (Culvert 104 – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing satisfies the Town design flood frequency criteria and the recommended safe access/egress criteria for flow overtopping the trail . The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (875 mm CSP) has a capacity of approximately 1.5 m3/s which corresponds to a 1:5-year design flood frequency. However, the existing culvert crossing has a 1:2-year design flood frequency when future condition peak flows are considered. Project No. 55A In accordance with Scenario A as described in Section 8.3.2, Culvert 104 would be replaced with a 1200 mm CSP culvert to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 2.6 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Project No. 55F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 55A. This project would involve maintaining the existing Culvert 103. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 55F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 55F is recommended for inclusion in the preferred solution. As project No. 55F is the “Do Nothing” alternative, no further consideration needs to be given to Project 55. 9.19 WATERCOURSE 21 9.19.1 Project No. 56 (Culvert 206 – Highway 26) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the MTO design flood frequency criteria. Highway 26 is an MTO Highway and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2200 mm x 750 mm CSPA) has a capacity of approximately 2.0 m3/s which corresponds to a 1:5-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 206 would be replaced with 2 – 1390 mm x 970 mm CSPA culverts to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 4.0 m3/s, a design flood frequency of 1:25-years (satisfying MTO standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 56 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 56 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as all works can be completed with the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on a ditch which receives spill from Watercourse 21 and is not within the GSCA Regulated Area. 9.19.2 Project No. 57 (Culvert 205 Improvement – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (2 – 800 mm CSPs) has a capacity of approximately 1.0 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 205 would be replaced with 2 – 1200 mm CSP culverts to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 2.7 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 57 will have an overall positi ve impact on the project environments and will be beneficial to the watershed. As such Project No. 57 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as all works can be completed with the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on a ditch which receives spill from Watercourse 21 and is not within the GSCA Regulated Area. 9.19.3 Project No. 58 (Culvert 102 – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (1800 mm CSP) has a capacity of approximately 1.8 m3/s which corresponds to a 1:2- year design flood frequency. In accordance with Scenario A described in Section 8.3.2, an additional 1000 mm CSP culvert would be installed at Culvert 102 to satisfy the design flood frequency criteria. Additionally, approximately 10 m of Watercourse 21 would be improved from the downstream end of Culvert 102 to the upstream end of Culvert 101. The proposed culverts would have a capacity of approximately 4.5 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 58 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 58 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 21 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 21. 9.19.4 Project No. 59 (Floodplain Storage Expansion No. 15 – Georgian Trail) There is an opportunity to expand the existing floodplain storage area upstream of the culvert crossing the Georgian Trail (Culvert 102) to provide additional peak flow attenuation for major storms and reduce flooding downstream. Project No. 59A As part of this project, approximately 1.0 ha of area upstream of Culvert 102 would be cleared, excavated, and graded to create approximately 5,000 m3 of additional floodplain storage volume upstream of the culvert crossing. The existing watercourse banks would be maintained, and the floodplain storage area would only be engaged during significant flow events exceeding the capacity of the low flow channel. It is noted this project would require property permission from Ontario Parks (Craigleith Provincial Park) to allow the proposed works. The VO major system hydrologic model was updated to include proposed Floodplain Storage Expansion No. 15 to assess the impact of the project on the design storm peak flows. It was determined that this project would have a moderate impact on peak flows downstream in Watercourse 21 with the 1:25-year design storm peak flow being reduced by approximately 24%. Project 59F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 59A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 59F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 59F is recommended for inclusion in the preferred solution. As project No. 59F is the “Do Nothing” alternative, no further consideration needs to be given to Project 59. 9.20 WATERCOURSE 19 9.20.1 Project No. 60 (Culvert 95 – Arrowhead Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Arrowhead Road is a collector road and therefore has a 1:50-year design flood frequency. The existing culvert crossing (2 - 2050 mm x 1200 mm CSPAs) has a capacity of approximately 12.0 m3/s which corresponds to a 1:5-year design flood frequency. Project No. 60A In accordance with Scenario A as described in Section 8.3.2, Culvert 109 would be replaced with a 3 – 2400 mm CSP culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 33.6 m3/s, a design flood frequency of 1:50-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 60F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 60A. This project would involve maintaining the existing Culvert 95. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 60F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 60F is recommended for inclusion in the preferred solution. As project No. 60F is the “Do Nothing” alternative, no further consideration needs to be given to Project 60. 9.20.2 Project No. 61 (Floodplain Storage Expansion No. 14 – Arrowhead Road) There is an opportunity to expand the existing floodplain storage area upstream of the culvert crossing Arrowhead Road (Culvert 95) to provide additional peak flow attenuation for major storms and reduce flooding downstream. Project No. 61A As part of this project, approximately 0.5 ha of area upstream of Culvert 95 would be cleared, excavated, and graded to create approximately 4,500 m3 of additional floodplain storage volume upstream of the culvert crossing. The existing watercourse banks would be maintained, and the floodplain storage area would only be engaged during significant flow events exceeding the capacity of the low flow channel. It is noted this project would require property permission from Ontario Parks (Craigleith Provincial Park) to allow the proposed works. The VO major system hydrologic model was updated to include the proposed Floodplain Storage Expansion No. 14 to assess the impact of the project on the design storm peak flows. It was determined that this project would have a minimal impact on peak flows downstream in Watercourse 19 with the 1:25-year design storm peak flow being reduced by approximately 4%. Project No. 61F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 61A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 61F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 61F is recommended for inclusion in the preferred solution. As project No. 61F is the “Do Nothing” alternative, no further consideration needs to be given to Project 61. 9.20.3 Project No. 62 (Culvert 96 – Alta Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria or the recommended safe access/egress criteria for flow overtopping the road. Alta Road is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2 – 1900 mm x 1200 mm ellipse CSPs) has a capacity of approximately 8.6 m3/s which corresponds to a 1:2- year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 96 would be replaced with a 4800 mm x 2100 mm box culvert to satisfy the design flood frequency criteria. To accommodate the proposed culvert, it is required to improve Watercourse 19 from approximately 10 m upstream of Culvert 96 to approximately 10 m downstream of Culvert 96. The proposed culvert would have a capacity of approximately 25.9 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 62 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 62 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition, however, permission to complete the works from the owner of PLAN 1134 BLK21 will be required as the proposed works extend onto private property. The proposed culvert improvement is a Schedule A+ project. The culvert improvement is located on Watercourse 19 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 19. 9.21 WATERCOURSE 15 9.21.1 Project No. 63 (Culvert 90 – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (2150 mm x 1250 mm CSPA) has a capacity of approximately 2.1 m 3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 90 would be replaced with a 2230 mm x 1700 mm CSPA culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert, it is required to improve Watercourse 15 from approximately 5 m upstream of Culvert 90 to approximately 5 m downstream of Culvert 90. The proposed culvert would have a capacity of approximately 4.5 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 63 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 63 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 15 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 15. 9.21.2 Project No. 64 (SWMF 15402 Retrofit/Expansion) The existing conditions analysis completed as part of this Drainage Master Plan determined that this existing SWMF does not provide the required active storage volume to control the 1:100- year peak flow and only provides Basic level water quality treatment (60% total suspended solids removal). There is an opportunity to expand and retrofit this SWMF to provide improved peak flow attenuation and water quality treatment. Project No. 64A As part of this project, approximately 0.4 ha adjacent to the existing SWMF would be cleared, excavated, and graded to expand the active storage and permanent pool volumes of the SWMF. Additionally, the SWMF forebay would be expanded, the location and configuration of the outlet structure would be adjusted, and an emergency overflow spillway would be formalized. The proposed retrofit and expansion would allow SWMF 15402 to control peak flows for storms up to and including the 1:100-year design storm and would improve the SWMF to provide Enhanced level water quality treatment as per Provincial standards. The VO major system hydrologic model was updated to include the proposed SWMF 15402 retrofit to assess the impact of the project on the design storm peak flows. It was determined that this project would have a minor impact on peak flows downstream in Watercourse 15 with the 1:25-year design storm peak flow being reduced by approximately 7%. Project No. 64F This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 64A. This project would involve maintaining SWMF 15402 in its existing configuration. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 64F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 64F is recommended for inclusion in the preferred solution. As project No. 64F is the “Do Nothing” alternative, no further consideration needs to be given to Project 64. 9.21.3 Project No. 114 (Trunk Storm Sewer Improvement No. 4 – Arrowhead Road) The existing conditions analysis completed as part of this Drainage Master Plan determined there is an overland flow deficiency at Arrowhead Road. The deficiency occurs along approximately 300 m of the road from Arrowhead Crescent to Alpine Springs Court as the amount of overland flow results in flow depths exceeding the maximum value specified in the Town’s standards under the 1:100-year design storm. Project No. 114A There is an opportunity to resolve the existing overland flow deficiency described above by replacing the existing storm sewer along Arrowhead Road with a trunk storm sewer. The proposed trunk storm sewer has been sized to convey the 1:100 -year peak flow. The proposed trunk sewer would consist of approximately 85 m of 600 mm storm sewer and 240 m of 900 mm storm sewer and would discharge to Watercourse 15 at the same location as the existing storm sewer. Project No. 114F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 114A. This project would involve maintaining the existing storm sewer system in Arrowhead Road. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 114A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 114A is recommended for inclusion in the preferred solution. The proposed trunk storm sewer improvement does not require property acquisition as t he works can be completed within the road allowance. The proposed improvement is a Schedule A project. The improvement is located on Arrowhead Road. The sewer outlet is located within the GSCA Regulated Area and therefore the works will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 15. 9.22 WATERCOURSE 14 9.22.1 Project No. 65 (Culvert 77 Improvement – Georgian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing satisfies the Town design flood frequency criteria and the recommended safe access/egress criteria for flows overtopping the road. The Georgian Trail is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (2130 mm x 1400 mm CSPA) has a capacity of approximately 4.7 m3/s which corresponds to a 1:10-year design flood frequency. In accordance with Scenario G described in Section 8.3.2, Culvert 77 would be replaced with 2 – 1600 mm CSP culverts embedded with 300 mm of natural substrate to match the capacity of the proposed culvert improvement upstream at Lakeshore Road West (Culvert 78) under Project No. 66. To accommodate the proposed culvert, it is required to improve Watercourse 14 from approximately 5 m upstream of Culvert 77 to approximately 5 m downstream of Culvert 77. The proposed culvert would have a capacity of approximately 6.5 m3/s, a design flood frequency of 1:10-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 65 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 63 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. However, it is recommended the Town purchase (or acquire an easement over) the portion of 209589 Highway 26 that Watercourse 14 runs through, to allow the Town to maintain the outlet of the watercourse. The proposed culvert improvement is a Schedule A project, or a schedule B project if property acquisition is pursued. The culvert improvement is located on Watercourse 14 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 14. 9.22.2 Project No. 66 (Culvert 78 – Lakeshore Road West) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria or the recommended safe access/egress criteria for flows overtopping the road. Lakeshore Road West is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2130 mm x 1400 mm CSPA) has a capacity of approximately 5.0 m3/s which corresponds to a 1:10-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 78 would be replaced with 2 – 1600 mm CSP culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert, it is required to improve Watercourse 14 from approximately 8 m upstream of Culvert 78 to approximately 5 m downstream of Culvert 78. The proposed culverts would have a capacity of approximately 7.5 m3/s, a design flood frequency of 1:50-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 66 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 66 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 14 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Revi ew will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 14. 9.22.3 Project No. 67 (Culvert 84 – Aspen Way) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flows overtopping the road. Aspen Way is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (1600 mm CSP) has a capacity of approximately 4.8 m3/s which corresponds to a 1:10-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 84 would be replaced with 2 – 1400 mm CSP culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 6.5 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 67 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 67 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 14 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 14. 9.22.4 Project No. 68 (Floodplain Storage Area Expansion No. 13 – Nippising Ridge Park) There is an opportunity to expand the existing floodplain storage area along Watercourse 14 through Nippising Ridge Park to provide additional peak flow attenuation for major design storms and reduce flooding downstream. Project No. 68A As part of this project, approximately 1.0 ha of area in Nippising Ridge Park would be cleared, excavated, and graded to create approximately 6,000 m3 of additional floodplain storage volume. A new culvert crossing would be installed along Watercourse 14 at the north limit of the park to restrict high flows (exceeding the channel capacity) and engage the floodplain storage area. The existing watercourse banks would be maintained, and the floodplain storage area would only be engaged during significant flow events exceeding the capacity of the low flow channel. The VO major system hydrologic model was updated to include the proposed Floodplain Storage Expansion No. 13 to assess the impact of the project on the design storm peak flows. It was determined that this project would have a moderate impact on peak flows downstream in Watercourse 14 with the 1:25-year design storm peak flow being reduced by approximately 22%. Project No. 68F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 68A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 68F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 68F is recommended for inclusion in the preferred solution. As project No. 68F is the “Do Nothing” alternative, no further consideration needs to be given to Project 68. 9.22.5 Project No. 69 (Culvert 85 – Blueski George Crescent) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flows overtopping the road. Blueski George Crescent is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (1600 mm CSP) has a capacity of approximately 3.0 m3/s which corresponds to a 1:5- year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 85 would be replaced with 2 – 1400 mm CSP culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 5.2 m3/s, a design flood frequency of 1:50-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 69 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 69 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 14 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 14. 9.22.6 Project No. 70 (Culvert 87 – Arrowhead Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flows overtopping the road. Arrowhead Road is a collector road and therefore has a 1:50-year design flood frequency. The existing culvert crossing (1150mm x 820 mm CSPA) has a capacity of approximately 1.8 m3/s which corresponds to a less than 1:2-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 87 would be replaced with 2 – 1630mm x 1120 mm CSPA culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert crossing it is required to improve Watercourse 14 from approximately 12 m upstream of Culvert 87 to approximately 10 m downstream of Culvert 87. The proposed culverts would have a capacity of approximately 5.7 m3/s, a design flood frequency of 1:50-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 70 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 70 is recommended for inclusion in the preferred solution. As part of this project, it is recommended that the Town purchase (or acquire an easement over) the portion of 274 Arrowhead Road through which Watercourse 14 passes. This property acquisition will coincide with a portion of the Watercourse 14 improvements required and will provide access for the Town to conduct maintenance on this section of the watercourse in the future. The proposed culvert improvement is a Schedule B project. The culvert improvement is located on Watercourse 14 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 14. 9.22.7 Project No. 71 (Culvert 88 – Arrowhead Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flows overtopping the road. This section of Arrowhead Road is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (800 mm CSP) has a capacity of approximately 1.1 m3/s which corresponds to a less than 1:2-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 88 would be replaced with 2 – 1200 mm CSP culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert crossing it is required to improve Watercourse 14 from approximately 10 m upstream of Culvert 88 to approximately 5 m downstream of Culvert 88. The proposed culverts would have a capacity of approximately 4.8 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 71 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 70 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 14 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 14. 9.23 OUTLET 13 9.23.1 Project No. 72 (SWMF Creation No. 12) There is an opportunity to create a new stormwater management facility to improve water quality treatment within the Outlet 13 watershed. This proposed SWMF would have a drainage area of approximately 31.0 ha (most of which is undeveloped, steeply sloped lands). Project No. 72A As part of this project, approximately 0.4 ha of vacant land at Sleepy Hollow Road and Aspen Way would be cleared, excavated, and graded to create a new wet pond stormwater management facility to provide water quality treatment for the Sleepy Hollow Road storm sewer. This project would include redirecting low flows (flows from the 25mm storm and less) to the proposed SWMF for water quality treatment. The proposed SWMF would provide Enhanced level water quality treatment for its drainage area. The proposed SWMF would discharge back into the Sleepy Hollow Road storm sewer system at Aspen Way. The VO major system hydrologic model was updated to include the proposed SWMF Creation No. 12 to assess the impact of the project on the design storm peak flows. It was determined that this project would have a minimal impact on peak flows in the downstream storm sewer system with the 1:5-year design storm peak flow being reduced by approximately 5%. Project No. 72F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 72A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 72F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 72F is recommended for inclusion in the preferred solution. As project No. 72F is the “Do Nothing” alternative, no further consideration needs to be given to Project 72. 9.24 WATERCOURSE 10 9.24.1 Project No. 73 (Watercourse 10 Improvements at Lakeshore Road East) The existing conditions analysis completed as part of this Drainage Master Plan determined that the culvert crossing at Lakeshore Road East (Culvert 72) does not satisfy the Town design flood frequency criteria and can cause flow to spill east upstream of Lakeshore Road East. Lakeshore Road East is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (900 mm CSP) has a capacity of approximately 0.8 m3/s which corresponds to a less than 1:2-year design flood frequency. The outlet for Watercourse 10 is a 2000 mm x 1000 mm CSPA culvert which crosses under Highway 26 and an existing private driveway before discharging to Georgian Bay. This culvert outlet is not being considered for improvement and therefore it’s capacity must be considered for the design of improvements at Lakeshore Road East upstream. Project No. 73G In accordance with Scenario G as described in Section 8.3.2, Culverts 72, 71, 70, and 69 would be replaced with 1880 mm x 1260 mm CSPA culverts. To accommodate the proposed culverts, it is required to improve Watercourse 10 from approximately 10 m upstream of Culvert 72 to approximately 30 m downstream of Culvert 70. The proposed culvert at Lakeshore Road East would have a capacity of approximately 3.7 m3/s, a design flood frequency of 1:2-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. This project would improve the capacity of this section of Watercourse 10 to an approximately 1:5-year design flood frequency matching the capacity of the existing culvert outlet to Georgian Bay (Culvert 68). Project No. 73E Under this project: ▪ Culverts 72, 71, 70, and 69 would be replaced with 1880 mm x 1260 mm CSPA culverts; ▪ the driveway culvert at 142 Lakeshore Road East would be replaced with an 1880 mm x 1260 mm CSPA culvert; ▪ an additional culvert crossing Lakeshore Road East would be installed approximately 130 m east of Culvert 72; ▪ the existing 2 – 900 mm CSP culverts crossing the Georgian Trail (Culvert 69) would be replaced with 2 – 1880 mm x 1260 mm CSPA culverts; ▪ the ditch along the north side of the Georgian Trail would be regraded to direct additional flows to Outlet 11; and ▪ the existing Outlet 11 culvert crossing Highway 26 (Culvert 74) would be replaced with an 1880 mm x 1260 mm CSPA culvert. The proposed culverts at Lakeshore Road East would have a capacity of approximately 7.4 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. This project would improve the combined capacity of Watercourse 10 and Outlet 11 to a 1:10-year design flood frequency from Lakeshore Road East to Georgian Bay. Project No. 73H Under this project: ▪ Culverts 72, 71, 70, and 69 would be replaced with 1880 mm x 1260 mm CSPA culverts; ▪ the driveway culvert at 142 Lakeshore Road East would be replaced with an 1880 mm x 1260 mm CSPA culvert; ▪ the existing 450 mm CSP culvert crossing Lakeshore Road East approximately 225 m east of Watercourse 10 would be replaced with an 1180 mm x 1260 mm CSPA; ▪ the overflow channel from Watercourse 9 to Outlet 8 proposed as part of the Drainage Act works would be expanded for additional capacity; ▪ the improvement of Culvert 61 proposed as part of the Drainage Act works would be increased from 2 – 1880 mm x 1260 mm CSPA culverts to 3 – 1880 mm x 1260 mm CSPA culverts; and ▪ the improvement of Culvert 60 proposed as part of the Drainage Act works would be increased from 2 – 1800 mm x 1200 mm concrete box culverts to 2 – 2400 mm x 1200 mm concrete box culverts. The proposed culverts at Lakeshore Road East would have a capacity of approximately 7.5 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. This project would improve the capacity of Watercourse 10 to a 1:10-year design flood frequency from Lakeshore Road East to Georgian Bay. Project No. 73F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternatives under Project No. 73. This project would involve maintaining the existing culverts on Watercourse 10 and Outlet 11 from Lakeshore Road East to Georgian Bay. Evaluation The individual project evaluation completed for the three options developed demonstrates that Project No. 73E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 73E is recommended for inclusion in the preferred solution. The proposed improvement project does not require property acquisition as the works can be completed within Town owned lands. The proposed improvement project is a Schedule B project. The improvement project is located on Watercourse 10 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 10. 9.24.2 Project No. 74 (Culvert 73 – Grey Road 19) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (1500 mm x 1100 mm CSPA) has a capacity of approximately 2.7 m 3/s which corresponds to a less than 1:2-year design flood frequency. Project No. 74A In accordance with Scenario A as described in Section 8.3.2, Culvert 73 would be replaced with a 4200 mm x 1200 mm box culvert to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to replace the existing driveway culvert at 796567 Grey Road 19 with a 4200 mm x 1200 mm box culvert as well. The proposed culvert would have a capacity of approximately 10.5 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 74E In accordance with Scenario E as described in Section 8.3.2, Culvert 73 would be replaced with a 3300 mm x 1200 mm box culvert. The proposed culvert would have a capacity of approximately 7.0 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road. Project No. 74G In accordance with Scenarios E and G as described in Section 8.3.2, Culvert 73 would be replaced with a 3300 mm x 1200 mm box culvert. To accommodate this proposed culvert, the existing driveway culvert at 796567 Grey Road 19 would be replaced with a 3300 mm x 1200 mm box culvert as well. The proposed culvert would have a capacity of approximately 7.0 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road. Project No. 74F This project is considered as a baseline for comparison against the proposed improvement alternatives under Project No. 74. This project would involve maintaining the existing Culvert 73. Evaluation The individual project evaluation completed for the four options developed demonstrates that Project No. 74G will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 74G is recommended for inclusion in the preferred solution on the condition that permission can be obtained from the owners of 796573 and 796567 Grey Road 19 to improve the existing driveway culvert on private property. If the Town is unable to obtain the permission required to implement Project No. 74G, then Project No. 74F is recommended. Property acquisition is not recommended as part of this project. However, permission from the owners of 796573 and 796567 Grey Road 19 will be required to complete the works proposed on private property. The proposed culvert improvement is a Schedule B project. The culvert improvement is located on Watercourse 10 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 10. 9.24.3 Project No. 75 (SWMF 10401 Retrofit/Expansion) The existing conditions analysis complete as part of this Drainage Master Plan determined that this existing SWMF does not provide the required active storage volume to control the 1:100- year peak flow and only provides Basic level water quality treatment (60% total suspended solids removal). There is an opportunity to expand and retrofit this SWMF to provide improved peak flow attenuation and water quality treatment. Project No. 75A As part of this project, the existing dry pond SWMF would be excavated and converted to a wet pond SWMF. Approximately 0.5 ha adjacent to the existing SWMF would be cleared, excavated, and graded to expand the active storage volume and permanent pool volumes of the SWMF. Additionally, a forebay would be added, the configuration of the outlet structure would be adjusted, and an emergency overflow spillway would be formalized. The proposed retrofit and expansion would allow SWMF 10401 to control peak flows for storms up to and including the 1:100-year design storm and would improve the SWMF to provide Enhanced level water quality treatment as per Provincial standards. To improve the effect SWMF 10401 has on reducing peak flows in Watercourse 10 downstream and increase the area being treated by the SWMF, a 450 mm storm sewer would be installed on Alexandra Way to divert flow from the Craigleith Road storm sewer into SWMF 10401. With this diversion, the effective drainage area of SWMF 10401 would be increased from approximately 6.2 ha to approximately 11.0 ha. The VO major system hydrologic model was updated to include the proposed SWMF 10401 retrofit and storm sewer diversion to assess the impact of the project on the design storm peak flows. It was determined that this project would have a moderate impact on peak flows downstream in Watercourse 10 with the 1:25-year design storm peak flow being reduced by approximately 28%. Project No. 75F This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 75A. This project would involve maintaining SWMF 10401 in its existing configuration. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 75A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 75A is recommended for inclusion in the preferred solution. The proposed SWMF improvement does not require property acquisition as the works can be completed within Town own lands. The proposed SWMF improvement is a Schedule B project. The SWMF improvement is not located within the GSCA regulated area and the proposed works do not require approval from the DFO. 9.25 WATERCOURSE 9 9.25.1 Project No. 76 (Culvert 66 – Grey Road 19) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (1500 mm CSP) has a capacity of approximately 3.1 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 76A In accordance with Scenario A as described in Section 8.3.2, Culvert 66 would be replaced with 2 – 2500 mm x 1830 mm CSPA culverts to satisfy the design flood frequency criteria. To accommodate this proposed culvert, it is required to improve Watercourse 9 from approximately 17 m upstream of the culvert crossing, to approximately 16 m downstream of the culvert crossing. The proposed culverts would have a capacity of approximately 14.2 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 76G In accordance with Scenario G as described in Section 8.3.2, Culvert 66 would be replaced with 2 – 2500 mm x 1830 mm CSPA culverts. To accommodate this proposed culvert, it is required to improve Watercourse 9 from approximately 17 m upstream of the culvert crossing, to approximately 16 m downstream of the culvert crossing. As part of this project, it is also required to replace the existing driveway culvert at 796531 Grey Road 19 with 2 – 2500 mm x 1830 mm CSPA culverts. The proposed culverts would have a capacity of approximately 14.2 m 3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 76F This project is considered as a baseline for comparison against the proposed improvement alternatives under Project No. 76. This project would involve maintaining the existing Culvert 66. Evaluation The individual project evaluation completed for the three options developed demonstrates that Project No. 76G will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 76G is recommended for inclusion in the preferred solution on the condition that permission can be obtained from the Owner of 796531 Grey Road 19 to improve the existing driveway culvert on private property. If the Town is unable to obtain the permission required to implement Project No. 76G, then Project No. 76F is recommended. Property acquisition is not recommended as part of this project. However, permission from the owners of 796531 Grey Road 19 will be required to complete the works proposed on private property. The proposed culvert improvement is a Schedule B project. The culvert improvement is located on Watercourse 9 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 9. 9.26 WATERCOURSE 7 9.26.1 Project No. 77 (Culvert 57 – Grey Road 19) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (2130 mm x 1400 mm CSPA) has a capacity of approximately 3.9 m 3/s which corresponds to a 1:2-year design flood frequency. Project No. 77A In accordance with Scenario A as described in Section 8.3.2, Culvert 57 would be replaced with a 4500 mm x 1200 mm box culvert to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 14.6 m3/s, a design flood frequency of 1:100- years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 77E In accordance with Scenario E as described in Section 8.3.2, Culvert 57 would be replaced with a 3600 mm x 1200 mm box culvert. This scenario would be less expensive and would have less potential to increase flooding downstream than the culvert improvement proposed under Project No. 77A. The proposed culvert would have a capacity of approximately 12.0 m3/s, a design flood frequency of 1:25-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 77E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 77E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 7 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 7. 9.27 DRAINAGE ACT IMPROVEMENTS As described in Section 1.2.4, there is a desire to address drainage issues on Watercourse 7, Outlet 8, and Watercourse 9 from Lakeshore Road East to Georgian Bay. Crozier Consulting Engineers has completed the conceptual design of drainage improvements for this area to address existing drainage deficiencies. The proposed drainage improvements are planned to be implemented through a petition under the Drainage Act, R.S.O. 1990, c. D.17. WT Infrastructure has completed a peer review of the proposed drainage improvements which is summarized in their Regional Stormwater Management Plan Watercourse 7, 8, 9 & 10 Municipal Drainage Act Assessment – Peer Review Report. WT Infrastructure has also prepared the Regional Stormwater Management Plan – Blue Mountain Diversion Drain – Drainage Act Assessment Report which summarizes the process of the proposed drainage improvements under the Drainage Act, R.S.O. 1990, c. D.17. Through the process of completing this Drainage Master Plan, Tatham has conducted a brief review of the proposed Drainage Act Improvements and is generally in agreement with the drainage improvements concept. We recommend that at the detailed design stage, the sizing of the proposed drainage improvements be confirmed in accordance with the hydrologic models developed as part of this Drainage Master Plan. For full details of the proposed improvements under the Drainage Act, please refer to the reports mentioned above, otherwise a summary of the proposed improvements is provided in the following sections. 9.27.1 Watercourse 9 Watercourse 9 is a municipal drain from Highway 26 to Georgian Bay referred to as the Ford Outlet Drian. Downstream of Highway 26, Watercourse 9 traverses approximately 100 m along the property line between 209683 Highway 26 and 209685 Highway 26 before discharging to Georgian Bay. This section of Watercourse 9 from Highway 26 to Georgian Bay has limited capacity and the existing structures on the adjacent private properties are near the channel banks (within approximately 5 m). Given the limited capacity of the channel downstream of Highway 26, the proposed drainage improvements will divert flows exceeding the capacity of Watercourse 9 downstream of Highway 26 from Watercourse 9 to Outlet 8 via a proposed drainage channel upstream of the Georgian Trail. Outlet 8 will be improved to convey the flow diverted from Watercourse 9. 9.27.2 Outlet 8 Outlet 8 downstream of Highway 26 traverses approximately 40 m of municipally owned property prior to discharging to Georgian Bay. Outlet 8 is a municipal drain (referred to as the Blue Mountain Diversion Drain) which currently receives overflow from Watercourse 7 via a relief culvert located along the Highway 26 south roadside ditch. The proposed Drainage Act improvements will increase the capacity of the Outlet 8 culverts crossing the Georgian Trail and Highway 26 and increase the capacity of the Outlet 8 channel from the Georgian Trail to Georgian Bay. These improvements to Outlet 8 will allow for additional flow to be directed to Outlet 8 from Watercourse 9 and Watercourse 7 to improve the drainage conditions of the surrounding area. 9.27.3 Watercourse 7 Watercourse 7 is a municipal drain from Highway 26 to Georgian Bay referred to as the Blue Mountain Drain. Downstream of Highway 26, Watercourse 7, traverses approximately 35 m along the property line between 209725 Highway 26 and 209727 Highway 26 before discharging to Georgian Bay. This section of the watercourse has very limited capacity and the existing structures on private property adjacent to this section of Watercourse 7 are located directly at the top of the channel banks. Previously, a relief culvert and ditch along the south side of Highway 26 were constructed to divert flow from Watercourse 7 to Outlet 8. Given the limited capacity of the channel downstream of Highway 26, the proposed improvements under the Drainage Act will divert flows exceeding the capacity of Watercourse 7 from Watercourse 7 to Outlet 8 via a proposed drainage channel upstream of the Georgian Trail. Outlet 8 will be improved to convey the additional flow diverted from Watercourse 7. 9.28 WATERCOURSE 6 9.28.1 Projects No. 78, 79, and 80 (Watercourse 6) The existing conditions analysis completed as part of this Drainage Master Plan identified an area of concern for flooding along the reach of Watercourse 6 from the Georgian Trail to Georgian Bay. There are numerous properties at risk along Highway 26, Timmons Street, Fraser Crescent and Blue Mountain Drive near Watercourse 6. Project No. 78 (Culvert 40 and Watercourse 6 Improvements) The existing culvert crossing Highway 26 (3650 mm x 1540 mm concrete box culvert) has a capacity of approximately 17.9 m3/s which corresponds to a 1:10-year design flood frequency. There is an opportunity to reduce the risk of flooding in this area by improving Watercourse 6 from the Georgian Trail to Georgian Bay and improving the existing culvert cr ossing Highway 26. Approximately 400 m of Watercourse would be improved, and the floodway would be expanded to increase the conveyance capacity of the watercourse. In accordance with Scenario A as described in Section 8.3.2, Culvert 40 would be replaced with a 12.2 m span structure to satisfy the design flood frequency criteria. The proposed span structure would have a capacity of approximately 28.0 m3/s, a design flood frequency of 1:100-years and would satisfy the safe access/egress criteria for flows overtopping Highway 26. The HEC-RAS 2D hydraulic model developed for this area of the Town was updated to reflect the watercourse and culvert improvements proposed under Project No. 78. The updated model determined these proposed improvements would greatly reduce the amount of flooding along this section of Watercourse 6 but would not completely eliminate flooding. It is also required to purchase 5 properties to accommodate the proposed watercourse floodway improvements. Project No. 79 (New Relief Outlet for Watercourse 6) There is an opportunity to reduce the risk of flooding in this area by creating a new relief channel to convey flood flows exceeding the capacity of Watercourse 6 to a new outlet between Watercourse 6 and Watercourse 7. The existing ditch al ong the south side of the Georgian Trail would be regraded and expanded from Watercourse 6 to Lakeshore Road East, a new culvert crossing (3000 mm x 1200 mm concrete box culvert) would be installed beneath Lakeshore Road East and the Georgian Trail, a new culvert crossing (3000 mm x 1200 mm concrete box culvert) would be installed beneath Highway 26, and an outlet channel would be constructed to Georgian Bay. The proposed relief channel and accompanying culvert crossings would have a capacity of approximately 10.0 m3/s. The HEC-RAS 2D hydraulic model developed for this area of the Town was updated to reflect the new relief outlet improvements proposed under Project No. 79. The updated model determined these proposed improvements would greatly reduce the amount of flooding along this section of Watercourse 6 but would not completely eliminate flooding. It is also required to purchase a portion of 209741 Highway 26 to accommodate the construction of the new outlet proposed under this project. Project No. 79E (Convey Overflow from Watercourse 6 to Improved Outlet 8) There is an opportunity to reduce the risk of flooding along Watercourse 6 by creating a new relief channel to convey flood flows exceeding the capacity of Watercourse 6 to Outlet 8 which is proposed to be improved as part of the Drainage Act improvements described in Section 9.27. Under this project: ▪ the existing ditch along the south side of the Georgian Trail would be regraded and expanded from Watercourse 6 to Lakeshore Road East; ▪ a new culvert crossing (3000 mm x 1200 mm concrete box culvert) would be installed beneath Lakeshore Road East and the Georgian Trail; ▪ the Highway 26 south roadside ditch would be regraded and expanded from Lakeshore Road East to Watercourse 7; ▪ the capacity of the existing Watercourse 7 culvert crossing Highway 26 would be reduced to the capacity of the downstream channel; ▪ the existing relief culvert (1500 mm x 900 mm elliptical concrete) would be removed; ▪ the Highway 26 south roadside ditch would be regraded and expanded from Watercourse 7 to Outlet 8; and ▪ the Outlet 8 culvert crossing improvement at Highway 26 proposed under the Drainage Act Improvements would be enlarged to convey the additional flow from Watercourse 6. The HEC-RAS 2D hydraulic model developed for this area of the Town was updated to reflect the new relief outlet improvements proposed under Project No. 79E. The proposed relief channel and accompanying culvert crossings would have a capacity of approximately 10.0 m3/s. The updated model determined these proposed improvements would greatly reduce the amount of flooding along Watercourse 6 downstream of the Georgian Trail but would not completely eliminate flooding. Project No. 80 (Floodplain Storage Expansion No. 2) There is an opportunity to reduce the risk of flooding in this area and attenuate peak flows by expanding the volume of existing floodplain storage in the existing wetland adjacent to Watercourse 6 upstream of the Georgian Trail. Under existing conditions, flow spills over the Georgian Trail from Watercourse 6 under the 1:25-year and greater design storms. This project would involve raising the Georgian Trail between Lakeshore Road East and Grey Road 21 to eliminate the spill and increase the amount of storage volume in the wetland upstream of the Georgian Trail to attempt to attenuate peak flows. The HEC-RAS 2D hydraulic model developed for this area of the Town was updated to reflect the Georgian Trail modifications proposed under Project No. 80. The updated model determined the modifications to the Georgian Trail would result in little additional floodplain storage. Hence, the results showed negligible attenuation of peak flows and eliminating the spill over the Georgian Trail increased flooding along Watercourse 6 from the Georgian Trail to Georgian Bay. Evaluation The following combinations of Projects No. 78, 79, and 80 were assessed and evaluated: ▪ Project No. 78; ▪ Project No. 79A; ▪ Project No. 79E; ▪ Project No. 80; ▪ Project No. 78 + Project No. 80; ▪ Project No. 79E + Project No. 80; ▪ Project No. 78 + Project No. 79E + Project No. 80; and ▪ Project No. 78F + Project No. 79F + Project No. 80F (Do Nothing). As project 79E scored better than Project 79A in the individual project evaluation, only Project 79E was considered in combination with Projects 78 and 80. The individual project evaluation completed for the combinations of options as described above demonstrates that Project No. 79E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 79E is recommended for inclusion in the preferred solution on the condition the work can be coordinated and completed in conjunction with the proposed improvements to Outlet 8 being completed through the Drainage Act as described in section 9.27. If Project 79E can not be coordinated with the Drainage Act works, then Project 79A is recommended for inclusion in the preferred solution. Both proposed projects (79E and 79A) are Schedule C projects and therefore will require additional assessment under a Schedule C Municipal Class EA process . Also, any proposed improvements to Outlet 8 (the Blue Mountain Diversion Drain) must proceed through a Drainage Act process. The projects are located near Watercourses 6 and 7 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for these projects. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for the applicable reaches of Watercourse 6, Watercourse 7, and Outlet 8. 9.28.2 Project No. 81 (SWMF Creation No. 9) There is an opportunity to create a new stormwater management facility to improve water quality treatment within the Watercourse 6 watershed. This proposed SWMF would have a drainage area of approximately 5.0 ha. Project No. 81A As part of this project, approximately 0.3 ha of vacant land at Tyrolean Lane and Kandahar Lane would be cleared, excavated, and graded to create a new wet pond stormwater management facility to provide water quality treatment for the local area. This project would include redirecting flows from the Tyrolean Lane roadside ditch to the proposed SWMF for water quality treatment. The proposed SWMF would provide Enhanced level water quality treatment for its drainage area as per Provincial standards. The proposed SWMF would discharge back to the culvert crossing Tyrolean Lane which drains to a tributary of Watercourse 6. The VO major system hydrologic model was updated to include proposed SWMF Creation No. 9 to assess the impact of the project on the design storm peak flows downstream. It was determined that this project would have a minor impact on peak flows in the downstream tributary with the 1:25-year design storm peak flow being reduced by approximately 12%. However, the impact of the proposed SWMF on peak flows in the main branch of Watercourse 6 is negligible. Project No. 81F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 81A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 81F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 81F is recommended for inclusion in the preferred solution. As project No. 81F is the “Do Nothing” alternative, no further consideration needs to be given to Project 81. 9.28.3 Project No. 82 (Culvert 44 – Arlberg Crescent) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency. Arlberg Crescent is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (1900 mm x 1500 mm CSPA) has a capacity of approximately 8.0 m3/s which corresponds to a 1:5-year design flood frequency. In accordance with Scenario G described in Section 8.3.2, Culvert 44 would be replaced with a 5100 mm x 1500 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria and improve the capacity of Culvert 45 upstream . The proposed culvert would have a capacity of approximately 16.5 m3/s, a design flood frequency of 1:50-years (exceeding Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 82 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 82 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.4 Project No. 83 (Culvert 45 – Brooker Boulevard) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Brooker Boulevard is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2060 mm x 1500 mm CSPA) has a capacity of approximately 3.5 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 45 would be replaced with a 5100 mm x 1200 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 12.3 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation completed demonstrates that Project No. 83 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 83 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.5 Project No. 84 (Culvert 46 – Brooker Boulevard) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Brooker Boulevard is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2100 mm x 1300 mm CSPA) has a capacity of approximately 5.7 m 3/s which corresponds to a 1:5-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 46 would be replaced with a 4500 mm x 1200 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 14.2 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation completed demonstrates that Project No. 84 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 84 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.6 Project No. 85 (Culvert 47 – Kandahar Lane) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency. Kandahar Lane is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2000 mm x 1500 mm CSPA) has a capacity of approximately 5.5 m3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 47 would be replaced with a 3900 mm x 1800 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert crossing it is required to improve Watercourse 6 from approximately 10 m upstream of Culvert 47 to approximately 10 m downstream of Culvert 47. The proposed culvert would have a capacity of approximately 9.7 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 82 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 82 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.7 Project No. 86 (SWMF Creation No. 7) There is an opportunity to create a new stormwater management facility to improve water quality treatment and peak flow attenuation within the Watercourse 6 watershed. This proposed SWMF would have a drainage area of approximately 12.8 ha of developed residential lands which currently drain uncontrolled. Project No. 86A As part of this project, approximately 0.4 ha of vacant land at Heritage Park on Kandahar Lane would be cleared, excavated, and graded to create a new wet pond stormwater management facility to provide water quality treatment and attenuation of flows from the residential lands on Settlers Way. The proposed SWMF would provide Enhanced level water quality treatment for its drainage area as per Provincial standards. The proposed SWMF would discharge back to the existing ditch at Kandahar Lane and Arlberg Crescent. The VO major system hydrologic model was updated to include proposed SWMF Creation No. 7 to assess the impact of the project on the design storm peak flows. It was determined that this project would have a moderate impact on peak flows in the downstream ditches and culverts system with the 1:25-year design storm peak flow being reduced by approximately 25%. However, the proposed SWMF has a minimal impact on peak flows in Watercourse 6 downstream as the 1:25-year flow is reduced by only 3%. Project No. 86F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 86A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 86F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 86F is recommended for inclusion in the preferred solution. As project No. 86F is the “Do Nothing” alternative, no further consideration needs to be given to Project 86. 9.28.8 Project No. 87 (Culvert 48 – Settlers Way) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency. Settlers Way is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2000 mm x 1500 mm CSPA) has a capacity of approximately 6.4 m3/s which corresponds to a 1:10- year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 48 would be replaced with a 3000 mm x 1800 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert crossing it is required to improve Watercourse 6 from approximately 8 m upstream of Culvert 48 to approximately 5 m downstream of Culvert 48. The proposed culvert would have a capacity of approximately 9.7 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 87 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 87 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.9 Project No. 88 (Culvert 49 – Settlers Way Path) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency. Settlers Way Path is a pedestrian trail and therefore has a 1:5-year design flood frequency. The existing culvert crossing (2000 mm x 1500 mm CSPA) has a capacity of approximately 2.9 m 3/s which corresponds to a 1:2-year design flood frequency. In accordance with Scenario A described in Section 8.3.2, Culvert 49 would be replaced with 2 – 1200 mm CSP culverts to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 5.6 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 88 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 88 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.10 Project No. 89 (Culvert 50 – Heritage Drive) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Heritage Drive is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2100 mm x 1500 mm CSPA) has a capacity of approximately 4.2 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 89A In accordance with Scenario A as described in Section 8.3.2, Culvert 46 would be replaced with 2 – 1600 mm CSP culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert crossing it is required to improve Watercourse 6 from approximately 10 m upstream of the culvert crossing to approximately 40 m downstream of the culvert crossing. The proposed culverts would have a capacity of approximately 9.2 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 89E In accordance with Scenario E as described in Section 8.3.2, Culvert 46 would be replaced with a 2500 mm x 1830 mm CSPA culvert embedded with 300 mm of natural substrate. This culvert improvement would not require watercourse improvements. The proposed culvert would have a capacity of approximately 7.5 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 89E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 89E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.11 Project No. 90 (Culvert 51 – Pioneer Lane) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Pioneer Lane is a local road and therefore has a 1:25-year design flood frequency. The existing culvert crossing (2130 mm x 1400 mm CSPA) has a capacity of approximately 4.2 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 90A In accordance with Scenario A as described in Section 8.3.2, Culvert 51 would be replaced with 2 – 2130 mm x 1400 mm CSPA culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert crossing it is required to improve Watercourse 6 from approximately 10 m upstream of the culvert crossing to approximately 75 m downstream of the culvert crossing (extending onto private property). The proposed culverts would have a capacity of approximately 9.7 m3/s, a design flood frequency of 1:5-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 90E In accordance with Scenario E as described in Section 8.3.2, Culvert 51 would be replaced with 2 – 1880 mm x 1260 mm CSPA culverts embedded with 300 mm of natural substrate. To accommodate the proposed culvert crossing it is required to improve Watercourse 6 within the municipal road allowance from approximately 3 m upstream of the culvert crossing to approximately 7 m downstream of the culvert crossing. The proposed culverts would have a capacity of approximately 5.3 m3/s, a design flood frequency of 1:5-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 90E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 90E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.12 Project No. 91 (Culvert 52 – Grey Road 19) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (1500 mm CSP) has a capacity of approximately 2.5 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 91A In accordance with Scenario A as described in Section 8.3.2, Culvert 52 would be replaced with 3 – 1930 mm x 1220 mm concrete ellipse culverts to satisfy the design flood frequency criteria. To accommodate the proposed culvert crossing it is required to im prove Watercourse 6 from approximately 5 m upstream of the culvert crossing to approximately 8 m downstream of the culvert crossing. The proposed culverts would have a capacity of approximately 13.1 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 91E In accordance with Scenario E as described in Section 8.3.2, Culvert 51 would be replaced with 2 – 1800 mm x 900 mm box culverts. This culvert improvement would not require watercourse improvements. The proposed culverts would have a capacity of approximately 7.3 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 91E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 91E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.13 Project No. 92 (Trunk Storm Sewer Improvement – Jozo Weider Boulevard / Lucille Wheeler Crescent) The existing conditions analysis completed as part of this Drainage Master Plan determined there is an overland flow deficiency at Jozo Weider Boulevard between Lucille Wheeler Crescent and Lucille Wheeler Lane and an overland flow deficiency on Lucille Wheeler Crescent at Grey R oad 19. The deficiencies in these areas are due to the depth of overland flow exceeding the maximum value specified in the Town’s standards under the 1:100-year design storm. Project No. 92A There is an opportunity to resolve the existing overland flow deficiency described above by replacing the existing storm sewer in Jozo Weider Boulevard and Lucille Wheeler Crescent with a trunk storm sewer. The proposed trunk storm sewer would be sized to convey the 1:100-year peak flow. The proposed trunk sewer would consist of approximately 275 m of 1050 mm storm sewer, 110 m of 1200 mm storm sewer and 35 m of 1350 mm storm sewer and would discharge to the Grey Road 19 north roadside ditch at the same location as the existing storm sewer. Project No. 92F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 92A. This project would involve maintaining the existing storm sewer system in Jozo Weider Boulevard and Lucille Wheeler Crescent. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 92F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 92F is recommended for inclusion in the preferred solution. As project No. 92F is the “Do Nothing” alternative, no further consideration needs to be given to Project 92. 9.28.14 Project No. 93 (SWMF Creation No. 5) There is an opportunity to create a new stormwater management facility to improve water quality treatment within the Watercourse 6 watershed. This proposed SWMF would have a drainage area of approximately 5.0 ha of developed residential and resort lands. Project No. 93A As part of this project, approximately 0.3 ha of vacant land at 796338 Grey Road 19 would be cleared, excavated, and graded to create a new wet pond stormwater management facility to provide water quality treatment of runoff from existing developed residential and parking lot lands. Runoff would be directed to the proposed SWMF from the existing Wintergreen Place roadside ditch. The proposed SWMF would provide Enhanced level water quality treatment for its drainage area as per Provincial standards. The proposed SWMF would discharge back to the Wintergreen Place roadside ditch approximately 70 m downstream. The VO major system hydrologic model was updated to include proposed SWMF Creation No. 5 to assess the impact of the project on the design storm peak flows. It was determined that this project would have a negative impact on the major storm peak flows in the downstream drainage system with the 1:25-year through 1:100-year design storm peak flows being increased by an average of approximately 13%. Project No. 93F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 93A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 93F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 93F is recommended for inclusion in the preferred solution. As project No. 93F is the “Do Nothing” alternative, no further consideration needs to be given to Project 93. 9.28.15 Projects No. 94 & 95 (Monterra Road / Watercourse 1 Drainage Improvements) The existing conditions analysis completed as part of this Drainage Master Plan determined there is a spill from Watercourse 1 towards Monterra Road which results in frequent flooding of Monterra Road as the local drainage system does not have capacity to convey the spill flows. The results of the analysis are supported by historical observations of flooding on Monterra Road and the adjacent properties. Project No. 94 (Monterra Road Drainage Improvements) There is an opportunity to improve the capacity of the Monterra Road drainage system to better convey the spill from Watercourse 1 and reduce the frequency and severity of the flooding historically observed. The proposed drainage improvements under Project No. 94 include improving both the north and south Monterra Road roadside ditches, improving the driveway culvert at 689798 Monterra Road (2 – 1800 mm x 900 mm concrete box culverts), improving the culvert crossing Monterra Road east of Grand Cypress Lane (2 – 2400 mm x 1200 mm concrete box culverts) and improving the drainage channel from the culvert crossing Monterra Road to Watercourse 6. The proposed driveway culvert at 689798 Monterra Road would have a capacity of approximately 5.5 m3/s which corresponds to a design flood frequency of 1:25-years. The proposed culvert crossing Monterra Road east of Grand Cypress Lane would have a capacity of approximately 10.3 m3/s which corresponds to a design flood frequency of 1:25-years. The HEC-RAS 2D hydraulic model developed for this area of the Town was updated to reflect the ditch and culvert improvements proposed under Project No. 94. The updated model determined these proposed improvements would greatly reduce the amount of flooding of Monterra Road and the adjacent private properties. Project No. 95 (Watercourse 1 and Grey Road 21 Drainage Improvements) There is an opportunity to improve Watercourse 1 and several of its culvert crossings to reduce the magnitude and frequency of the spill from Watercourse 1 towards Monterra Road and hence reduce the frequency and severity of the flooding historically observed at Monterra Road. The proposed drainage improvements under project No. 95 include improving Watercourse 1 from approximately 75 m downstream of Grand Cypress Lane to Grey Road 21 and improving the Watercourse 1 culvert crossings at Grey Road 21, Forest Drive, 319 Grey Road 21, 325 Grey Road 21, 343 Grey Road 21, and Silver Creek Drive. These proposed improvements would increase the conveyance capacity of Watercourse 1 and reduce the magnitude of the spill towards Monterra Road. The analysis completed for the improvements proposed under Project No. 95 determined the proposed improvements would result in a minor reduction in flooding at Monterra Road but would increase flooding of the properties adjacent to Watercourse 1 east of Grey Road 21. Project No. 94F + Project No. 95F – Do Nothing This project was considered as a baseline for comparison against the improvements proposed under projects No. 94 and 95. Under this project, the existing conditions would be maintained for the Monterra Road and Watercourse 21 drainage systems in the areas considered under Projects No. 94 and 95. Evaluation The individual project evaluation completed for the options as described above demonstrates that Project No. 94 will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 94 is recommended for inclusion in the preferred solution. The proposed improvements under Project No. 94 can be completed primarily within the road allowance, however permission from the owner of 302 Grey Road 21 will be required to complete the channel improvements downstream of Monterra Road. The proposed project is a Schedule B project. The project is located near Watercourses 1 and 6 and a portion of the proposed works are within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.16 Project No. 96 (Culvert 42 – Monterra Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Monterra Road is a collector road and therefore has a 1:50-year design flood frequency. The existing culvert crossing (1830 mm x 1150 mm CSPA) has a capacity of approximately 3.7 m3/s which corresponds to a 1:10-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 52 would be replaced with 2 – 2010 mm x 1530 mm CSPA culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 6.2 m3/s, a design flood frequency of 1:50-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 90 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 90 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 6 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 6. 9.28.17 Project No. 97 (SWMF 6408 Retrofit) The existing conditions analysis complete as part of this Dr ainage Master Plan determined that this existing SWMF does not provide extended detention storage and therefore does not provide adequate water quality treatment. There is an opportunity to retrofit the outlet of this SWMF to add an extended detention storage component to the SWMF and improve the water quality treatment provided by the SWMF. Project No. 97A As part of this project, the existing wet pond SWMF outlet structure would be modified to include a 200 mm diameter orifice approximately 0.5 m below the existing weir sill and permanent pool elevation. The proposed retrofit would allow SWMF 6408 to provide approximately 2,700 m3 of extended detention volume, 3,900 m3 of permanent pool volume and 5,700 m3 of active storage volume, all of which would be sufficient to provide Enhanced level water quality treatment as per Provincial standards. SWMF 6408 has a drainage area of approximately 26.5 ha of developed residential and resort lands. The VO major system hydrologic model was updated to include the propos ed SWMF 6408 retrofit to assess the impact of the project on the design storm peak flows in the downstream drainage system. It was determined that this project would have a negative impact on the major storm peak flows in the downstream drainage system with the 1:25-year through 1:100-year design storm peak flows being increased by an average of approximately 13%. Project No. 97F This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 96A. This project would involve maintaining SWMF 6408 in its existing configuration. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 97F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 97F is recommended for inclusion in the preferred solution. As project No. 97F is the “Do Nothing” alternative, no further consideration needs to be given to Project 97. 9.29 WATERCOURSE 2 Watercourse 2 is a municipal drain also known as the Long Point Municipal Drain . Given this feature is a municipal drain, from a planning and approvals perspective, this feature would be a good candidate for drainage improvements to attempt to alleviate some of the existing drainage issues along Watercourse 1 and Watercourse 6 nearby. However, from an engineering perspective, there is very limited opportunity to further utilize this drainage feature due to its lack of slope, low elevation relative to the system outlet at Georgian Bay, and backwater effects from Georgian Bay. A significant portion of Long Point Road adjacent to Watercourse 2 is only approximately 0.3 m above the Georgian Bay high-water level of 177.50 and is therefore susceptible to flooding. Due to these constraints and the existing drainage issues along Long Point Road, Watercourse 2 was pre-screened and eliminated from further evaluation for individual drainage solutions to alleviate flooding caused by high flows in Watercourses 1 and 6. 9.30 WATERCOURSE 1 9.30.1 Project No. 98 (Culvert 14 – Grey Road 19) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (1800 mm CSP) has a capacity of approximately 5.1 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 98A In accordance with Scenario A as described in Section 8.3.2, Culvert 14 would be replaced with a 5100 mm x 2100 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert crossing it is required to improve Watercourse 1 from approximately 25 m upstream of the culvert crossing to approximately 30 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 22.0 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 98E In accordance with Scenario E as described in Section 8.3.2, Culvert 14 would be replaced with a 4200 mm x 1800 mm box culvert embedded with 300 mm of natural substrate. To accommodate the proposed culvert crossing it is required to improve Watercourse 1 within the municipal road allowance from approximately 25 m upstream of the culvert crossing to approximately 7 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 16.0 m3/s, a design flood frequency of 1:50-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 98E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 98E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 1 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 1. 9.30.2 Project No. 99 (Culvert 15 – Campbell Crescent) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flow overtopping the road. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (1800 mm CSP) has a capacity of approximately 5.1 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 99A In accordance with Scenario A as described in Section 8.3.2, Culvert 15 would be replaced with a 4500 mm x 1500 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. To accommodate the proposed culvert crossing it is required to improve Watercourse 1 from approximately 10 m upstream of the culvert crossing to approximately 10 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 13.8 m3/s, a design flood frequency of 1:25-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 99E In accordance with Scenario E as described in Section 8.3.2, Culvert 15 would be replaced with a 3600 mm x 1500 mm box culvert embedded with 300 mm of natural substrate. This proposed culvert would be less expensive than the culvert proposed under Project No. 99A, and would provide a similar, albeit lower, level of service. To accommodate the proposed culvert crossing it is required to improve Watercourse 6 from approximately 10 m upstream of the culvert crossing to approximately 10 m downstream of the culvert crossing. The proposed culvert would have a capacity of approximately 10.5 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 99E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 99E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 1 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 1. 9.30.3 Project No. 100 (Culvert 17 – Gord Canning Drive) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Gord Canning Drive is a local road and therefore has a 1:25-year design flood frequency. However, this culvert crossing is at the roundabout which services Grey Road 19, an arterial road with a 1:100 -year design flood frequency. The existing culvert crossing (750 mm concrete pipe) has a capacity of approximately 1.4 m3/s which corresponds to a 1:10-year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 17 would be replaced with a 1350 mm concrete pipe to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 3.5 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 100 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 100 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Watercourse 1 within the GSCA Regulated Area and will require a permit from the GSCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Watercourse 1. 9.30.4 Project No. 115 (Culvert 13 – Crosswinds Boulevard) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria . Crosswinds Boulevard is a collector road and therefore has a 1:50-year design flood frequency. The existing culvert crossing (4500 mm x 1900 mm box culvert with 1000 mm embedment) has a capacity of approximately 10.2 m3/s which corresponds to a 1:10-year design flood frequency. Project No. 115A In accordance with Scenario A as described in Section 8.3.2, Culvert 13 would be replaced with a 4800 mm x 2100 mm box culvert embedded with 1000 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 16.0 m3/s, a design flood frequency of 1:50-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 115F This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 115A. This project would involve maintaining the existing Culvert 13. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 115F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 115F is recommended for inclusion in the preferred solution. As project No. 115F is the “Do Nothing” alternative, no further consideration needs to be given to Project 115. 9.30.5 Project No. 117 (SWMF Creation No. 3) There is an opportunity to create a new stormwater management facility to improve water quality treatment within the Watercourse 1 watershed. This proposed SWMF would have a drainage area of approximately 6.0 ha of developed residential lands. Project No. 117A As part of this project, approximately 0.3 ha of vacant land at PLAN 91 PT BLK B LOT 17 would be cleared, excavated, and graded to create a new wet pond stormwater management facility to provide water quality treatment of runoff from existing developed residential lands. Flow would be directed to the proposed SWMF from the existing Carmichael Crescent roadside ditch. The proposed SWMF would provide Enhanced level water quality treatment for its drainage area as per Provincial standards. The proposed SWMF would discharge back to Watercourse 1 approximately 100 m west of Grey Road 19. The VO major system hydrologic model was updated to include the proposed SWMF Creation No. 3 to assess the impact of the project on the design storm peak flows. It was determined that this project would have a minimal impact on peak flows in the Watercourse 1 downstream with the 1:25-year design storm peak flow being reduced by approximately 1%. Project No. 117F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 117A. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 117F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 117F is recommended for inclusion in the preferred solution. As project No. 117F is the “Do Nothing” alternative, no further consideration needs to be given to Project 117. 9.31 SILVER CREEK 9.31.1 Project No. 101 (Culvert 23 – Grey Road 21) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Grey Road 21 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (600 mm CSP) has a capacity of approximately 1.1 m3/s which corresponds to a 1:50- year design flood frequency. Project No. 101A In accordance with Scenario A as described in Section 8.3.2, Culvert 23 would be replaced with a 1000 mm CSP culvert to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 3.0 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 101F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 101A. This project would involve maintaining the existing Culvert 23. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 101F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 101F is recommended for inclusion in the preferred solution. As project No. 101F is the “Do Nothing” alternative, no further consideration needs to be given to Project 101. 9.31.2 Project No. 102 (Culvert 25 – Grey Road 21) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria , or the recommended safe access/egress criteria for flow overtopping the road. Grey Road 21 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (1400 mm x 750 mm CSPA) has a capacity of approximately 3.0 m3/s which corresponds to a less than 1:2-year design flood frequency. Project No. 102A In accordance with Scenario A as described in Section 8.3.2, Culvert 25 would be replaced with 2 – 1800 mm CSP culverts to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 23.0 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 102F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 102A. This project would involve maintaining the existing Culvert 25. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 102F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 102F is recommended for inclusion in the preferred solution. As project No. 102F is the “Do Nothing” alternative, no further consideration needs to be given to Project 102. 9.31.3 Project No. 103 (Culvert 27 – Pedestrian Trail Crossing) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Pedestrian trails have a 1:5-year design flood frequency. The existing culvert crossing (1880 mm x 1260 mm CSPA) has a capacity of approximately 2.5 m3/s which corresponds to a less than 1:2-year design flood frequency. Project No. 103A In accordance with Scenario A as described in Section 8.3.2, Culvert 27 would be replaced with 2 – 1600 mm CSP culverts to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 8.5 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Project No. 103F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 103A. This project would involve maintaining the existing Culvert 27. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 103F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 103F is recommended for inclusion in the preferred solution. As project No. 103F is the “Do Nothing” alternative, no further consideration needs to be given to Project 103. 9.31.4 Project No. 104 (Culvert 28 – Grey Road 19) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (1200 mm CSP) has a capacity of approximately 3.1 m3/s which corresponds to a 1:25- year design flood frequency. In accordance with Scenario A as described in Section 8.3.2, Culvert 28 would be replaced with a 2400 mm x 1200 mm box culvert to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 4.5 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Evaluation The individual project evaluation demonstrates that Project No. 104 will have an overall positive impact on the project environments and will be beneficial to the watershed. As such Project No. 104 is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on a tributary of Silver Creek within the NVCA Regulated Area and will require a permit from the NVCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Silver Creek. 9.31.5 Project No. 105 (Culvert 30 – Pedestrian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Pedestrian trails have a 1:5-year design flood frequency. The existing culvert crossing (2 – 1880 mm x 1260 mm CSPAs) has a capacity of approximately 5.5 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 105A In accordance with Scenario A as described in Section 8.3.2, Culvert 30 would be replaced with 3 – 1600 mm CSP culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 7.5 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Project No. 105F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 105A. This project would involve maintaining the existing Culvert 30. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 105F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 105F is recommended for inclusion in the preferred solution. As project No. 105F is the “Do Nothing” alternative, no further consideration needs to be given to Project 105. 9.31.6 Project No. 106 (Culvert 31 – Crosswinds Boulevard) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does satisfy the Town design flood frequency criteria and the recommended safe access/egress criteria for flow overtopping the road. Crosswinds Boulevard is a collector road and therefore has a 1:50-year design flood frequency. The existing culvert crossing (2400 mm x 1800 mm box culvert embedded 300 mm) has a capacity of approximately 11.5 m3/s which corresponds to a 1:50-year design flood frequency. However, under the future conditions analysis, this culvert crossing has a design flood frequency of 1:25-years (less than Town standard). Project No. 106A In accordance with Scenario A as described in Section 8.3.2, Culvert 31 would be replaced with a 2700 mm x 1800 mm box culvert embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 12.8 m3/s, a design flood frequency of 1:50-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Project No. 106F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 106A. This project would involve maintaining the existing Culvert 31. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 106F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 106F is recommended for inclusion in the preferred solution. As project No. 106F is the “Do Nothing” alternative, no further consideration needs to be given to Project 106. 9.31.7 Project No. 107 (Culvert 32 – Pedestrian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Pedestrian trails have a 1:5-year design flood frequency. The existing culvert crossing (1880 mm x 1260 mm CSPA) has a capacity of approximately 3.1 m3/s which corresponds to a less than 1:2-year design flood frequency. Project No. 107A In accordance with Scenario A as described in Section 8.3.2, Culvert 32 would be replaced with a 2 – 1880 mm x 1260 mm CSPA culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 5.6 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Project No. 107F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 107A. This project would involve maintaining the existing Culvert 32. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 107F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 107F is recommended for inclusion in the preferred solution. As project No. 107F is the “Do Nothing” alternative, no further consideration needs to be given to Project 107. 9.31.8 Project No. 108 (Culvert 33 – Pedestrian Trail) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Pedestrian trails have a 1:5-year design flood frequency. The existing culvert crossing (1880 mm x 1260 mm CSPA) has a capacity of approximately 3.2 m3/s which corresponds to a less than 1:2-year design flood frequency. Project No. 108A In accordance with Scenario A as described in Section 8.3.2, Culvert 33 would be replaced with 3 – 1880 mm x 1260 mm CSPA culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. As part of this project it is also required to regrade and raise approximately 50 m of the pedestrian trail at the culvert crossing to satisfy the design flood frequency criteria. The proposed culverts would have a capacity of approximately 5.7 m3/s, a design flood frequency of 1:5-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Project No. 108E In accordance with Scenario A as described in Section 8.3.2, Culvert 33 would be replaced with 2 – 1880 mm x 1260 mm CSPA culverts embedded with 300 mm of natural substrate. The proposed culverts would have a capacity of approximately 4.5 m3/s, a design flood frequency of 1:2-years (less than Town standards) and would satisfy the safe access/egress criteria for flow overtopping the trail when unobstructed. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 108E will have the greatest overall positive impact on the project environments an d will be most beneficial to the watershed. As such Project No. 108E is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within Town owned lands. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on a tributary of Silver Creek within the NVCA Regulated Area and will require a permit from the NVCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Silver Creek. 9.31.9 Project No. 109 (Culvert 34 – Grey Road 19) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does satisfy the Town design flood frequency criteria and the recommended safe access/egress criteria for flow overtopping the road. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (2400 mm x 1200 mm box culvert) has a capacity of approximately 9.2 m3/s which corresponds to a 1:100-year design flood frequency. However, under the future conditions analysis, this culvert crossi ng has a design flood frequency of 1:50-years (less than Town standard). Project No. 109A In accordance with Scenario A as described in Section 8.3.2, Culvert 34 would be replaced with a 2700 mm x 1200 mm box culvert embedded with 300 mm of natural substra te to satisfy the design flood frequency criteria. The proposed culvert would have a capacity of approximately 9.8 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 109F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 109A. This project would involve maintaining the existing Culvert 34. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 109F will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 109F is recommended for inclusion in the preferred solution. As project No. 109F is the “Do Nothing” alternative, no further consideration needs to be given to Project 109. 9.31.10 Project No. 110 (Culvert 37 – Grey Road 19) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (2000 mm x 1500 mm CSPA) has a capacity of approximately 5.0 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 110A In accordance with Scenario A as described in Section 8.3.2, Culvert 37 would be replaced with a 6.4 m open bottom span structure to satisfy the design flood frequency criteria. The proposed crossing would have a capacity of approximately 10.5 m3/s, a design flood frequency of 1:100- years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 110F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 110A. This project would involve maintaining the existing Culvert 37. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 110A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 110A is recommended for inclusion in the preferred solution on the condition that it is confirmed the proposed culvert improvement will not increase flooding along Silver Creek downstream. This study has not considered the reaches of Silver Creek outside of the Town of The Blue Mountains and therefore did not determine the downstream impact of the culvert improvement proposed under Project No. 110. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on a tributary of Silver Creek within the NVCA Regulated Area and will require a permit from the NVCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Silver Creek. 9.31.11 Project No. 111 (Culvert 38 – Grey Road 19) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flows overtopping the road. Grey Road 19 is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (5000 mm x 2500 mm CSPA) has a capacity of approximately 5.0 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 111A In accordance with Scenario A as described in Section 8.3.2, Culvert 38 would be replaced with a 10.3 m open bottom span structure to satisfy the design flood frequency criteria. The proposed crossing would have a capacity of approximately 70.9 m3/s, a design flood frequency of 1:100- years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 111F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 111A. This project would involve maintaining the existing Culvert 38. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 111A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 111A is recommended for inclusion in the preferred solution on the condition that it is confirmed the proposed culvert improvement will not increase flooding along Silver Creek downstream. This study has not considered the reaches of Silver Creek outside of the Town of The Blue Mountains and therefore did not determine the downstream impact of the culvert improvement proposed under Project No. 111. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on Silver Creek within the NVCA Regulated Area and will require a permit from the NVCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Silver Creek. 9.31.12 Project No. 112 (Bridge 39 – Sideroad 12) The existing conditions analysis completed as part of this Drainage Master Plan determined that this bridge crossing does not satisfy the Town design flood frequency criteria, or the recommended safe access/egress criteria for flows overtopping the road. Sideroad 12 is a local road and therefore has a 1:25-year design flood frequency. The existing bridge crossing (6.5 m span) has a capacity of approximately 15.3 m3/s which corresponds to a 1:2-year design flood frequency. Project No. 112E In accordance with Scenario E as described in Section 8.3.2, Bridge 39 would be replaced with a 10.3 m open bottom span structure. To accommodate the proposed span structure it is required to improve Silver Creek within the municipal road allowance. The proposed crossing would have a capacity of approximately 37.1 m3/s, a design flood frequency of 1:10-years (less than Town standards) and would reduce the depth of flooding for flows overtopping the road. Project No. 112F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 112E. This project would involve maintaining the existing Bridge 39. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 112E will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 112E is recommended for inclusion in the preferred solution on the condition that it is confirmed the proposed culvert improvement will not increase flooding along Silver Creek downstream. This study has not considered the reaches of Silver Creek outside of the Town of The Blue Mountains and therefore did not determine the downstream impact of the bridge improvement proposed under Project No. 112. The proposed culvert improvement does not require property acqu isition as the works can be completed within the road allowance. The proposed bridge improvement is a Schedule A project. The bridge improvement is located on Silver Creek within the NVCA Regulated Area and will require a permit from the NVCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Silver Creek. 9.31.13 Project No. 116 (Culvert 36 – Scenic Caves Road) The existing conditions analysis completed as part of this Drainage Master Plan determined that this culvert crossing does not satisfy the Town design flood frequency criteria. Scenic Caves Road is an arterial road and therefore has a 1:100-year design flood frequency. The existing culvert crossing (2 – 1800 mm x 900 mm box culverts) has a capacity of approximately 6.1 m3/s which corresponds to a 1:10-year design flood frequency. Project No. 116A In accordance with Scenario A as described in Section 8.3.2, Culvert 36 would be replaced with 2 – 2400 mm x 1500 mm box culverts embedded with 300 mm of natural substrate to satisfy the design flood frequency criteria. The proposed crossing would have a capacity of approximately 9.4 m3/s, a design flood frequency of 1:100-years (satisfying Town standards) and would satisfy the safe access/egress criteria for flow overtopping the road when unobstructed. Project No. 116F – Do Nothing This project is considered as a baseline for comparison against the proposed improvement alternative under Project No. 116A. This project would involve maintaining the existing Culvert 36. Evaluation The individual project evaluation completed for the two options developed demonstrates that Project No. 116A will have the greatest overall positive impact on the project environments and will be most beneficial to the watershed. As such Project No. 116A is recommended for inclusion in the preferred solution. The proposed culvert improvement does not require property acquisition as the works can be completed within the road allowance. The proposed culvert improvement is a Schedule A project. The culvert improvement is located on a tributary of Silver Creek within the NVCA Regulated Area and will require a permit from the NVCA. It is anticipated that a Request for Review will satisfy the requirements of the DFO for this project. The MNDMNRF should be consulted to establish the appropriate fishery timing windows for this reach of Silver Creek. 10 Preliminary Preferred Solution / Individual Drainage Projects The general recommendation applicable throughout the Town as well as the individual drainage projects included as part of the preliminary preferred solution developed through this Drainage Master Plan are outlined in the following sections. 10.1 GENERAL RECOMMENDATIONS The general recommendations described in the following sections are recommended for implementation throughout the Town where appropriate. 10.1.1 Alternative 2D – Lot Level Low Impact Development Measures The implementation of lot level Low Impact Development (LID) measures on private property across the Town will increase infiltration, improve the water balance and watershed water quality and will provide an overall benefit. The Town should promote the use of rain barrels and implementation of soakaway pits by residents and property owners in the Town. It is not recommended the Town invest in the capital costs associated with this improvement alternative as it provides negligible benefits to Town infrastructure performance and costs. 10.1.2 Alternative 2E – Linear Low Impact Development Measures The Town should implement perforated pipe systems or infiltration systems as part of local road reconstruction projects and intensification at specific locations within the Town where site conditions are favourable and existing constraints prevent the implementation of more effective flow reduction/water quality improvement options. Roads satisfying the pre-screening criteria described in Section 8.2.5 that are also located in a geographic area with soils favourable to infiltration and suitable groundwater levels should be given consideration for potential implementation of linear LID measures at the detailed design stage. 10.1.3 Alternative 2G – Mechanical Devices (Oil Grit Separators) It is recommended that the Town installs mechanical devices such as oil grit separators within the storm sewer network to address stormwater quality throughout the Town in areas where linear LIDs are not feasible. It is recommended that mechanical devices used in the Town be verified in accordance with the ISO 14034:2016 Environmental Technology Verification (ETV) process. Under existing conditions some locations within the Town provide very limited quality control and this negatively impacts the ecological health of the receiving water bodies. Land constraints limit the feasibility of widespread implementation of large-scale water quality improvement options such as stormwater management facilities or centralized LIDs. Therefore, implementation of Alternative 2G is recommended as an ‘end of pipe’ measure for storm systems which currently provide sub-standard water quality treatment. Implementation of Alternative 2G should be considered for all road reconstruction projects at the detailed design stage. 10.1.4 Alternative 3A – Minor Drainage System Improvements For all capital projects, it is recommended that upsizing local storm sewers to satisfy current design standards be considered as part of future road reconstruction projects . Similarly, it is recommended that relocation of minor drainage system infrastructure into the municipal right of way be considered as part of future road reconstruction projects. It is also recommended that streets absent of minor drainage systems be improved to include storm sewers , or as necessary roadside ditches, as part of future road reconstruction projects. 10.1.5 Alternative 3D – Drainage Outlets Design, Operation and Maintenance It is recommended the Town apply new criteria for the design and construction of drainage system outlets to Georgian Bay as part of the ongoing update to the Town Engineering Standards. These design criteria should include considerations for: ▪ Provision of appropriate setbacks of drainage structures from the shoreline; ▪ Setting drainage structures at appropriate elevations with respect to the historic high-water levels of Georgian Bay; ▪ Provision of shoreline protection and measures to mitigate the impact of wave uprush and material deposition on outlet structures and channels; and ▪ Requirements for coastal engineering design of outlet structures and shoreline protection measures where applicable. Additionally, it is recommended the Town establish a formal procedure for inspection, operation and maintenance of the Town-owned drainage outlets across the Town and outlets located on private property which convey municipal drainage. The procedure should include: ▪ A comprehensive list of Town-owned drainage outlets; ▪ A standard inspection procedure including guidelines for frequency of inspections, inspection checklists and indicators triggering maintenance; ▪ Considerations to adjust inspection timing following significant storm events and periods of high or low water levels in Georgian Bay; and ▪ Standard maintenance procedures including considerations for permitting requirements and environmental constraints. The Town has been inspecting and maintaining several drainage outlets during recent years. The outlets the Town has been maintaining are listed in Table 21. It is noted this list is not a complete and comprehensive list of drainage outlets across the Town and it is recommended this list be expanded upon through the recommended formalized drainage outlet inspection, operation, and maintenance program. Table 21: Current List of Drainage Outlets Inspected and Maintained by The Town OUTLET ID LOCATION OUTLET ID LOCATION 1 Between 159 and 161 Sunset Blvd 11 Between 133 and 131 Bayview Ave 2 End of 39th Sideroad 12 Between 113 and 115 Bayview Ave 3 West of Sunset Sewage Lift Station (373 Sunset Blvd) 13 West of 208535 Highway 26 4 End of 10th Line (Intersection with Lake Dr and Cameron St) 14 187 Lakewood Dr 5 End of Peel St N (North of Thornbury Water Treatment Plant) 15 South-East of Council Beach (beside 208653 Highway 26) 6 West of 116 Lakeshore Drive 16 End of Camperdown Rd 7 East of Elgin Sewage Lift Station (50 Elgin St N) 17 Between 117 and 123 Teskey Dr 8 End of Grey St N (Between 194 and 182 Bay St E) 18 West of 143 Blue Mountain Dr 9 Between 230 and 183 Bayview Ave 19 Between 201 and 203 Brophy's Lane 10 Between 171 and 169 Bayview Ave 20 South of 204 Long Point Rd It is also recommended under this alternative that the Town proactively seek to acquire property or easements over existing drainage outlets located on private property which convey municipal drainage. 10.1.6 Alternative 3E – Drainage System Operation and Maintenance It is recommended the Town formalize their procedure for the inspection, operation and maintenance of Town-owned culvert crossings, stormwater management facilities, and mechanical treatment devices. The procedure should include: ▪ A comprehensive list of Town-owned culverts, stormwater management facilities, and mechanical treatment devices; ▪ A standard inspection procedure including guidelines for frequency of inspections, inspection checklists and indicators triggering maintenance; ▪ Considerations to adjust inspection timing following significant storm events or reported drainage issues; and ▪ Standard maintenance procedures including considerations for permitting requirements and environmental constraints. This formal inspection, operation and maintenance program will allow the Town to improve its approach to operation and maintenance as records are created which will illustrate which components of the Town’s drainage system require the most frequent attention. 10.2 INDIVIDUAL DRAINAGE SOLUTIONS (PROJECTS) The individual projects recommended as part of the preliminary preferred solution along with their cost, EA status, archaeological, cultural and natural heritage constraints and approval requirements are summarized in the following table. The Preliminary Preferred Solutions maps (Drawings 8A – 8H) illustrating the locations of the recommended projects are provided overleaf. Conceptual design drawings for each recommended project are enclosed in Appendix H and project cost estimates are included in Appendix J for reference. Table 22: Preliminary Preferred Solution Summary Impr .ame/ID • Location Description afiligniapital Climb Property Acquisition VA Schedule Watercourse 55 1A Culvert No. 198 / TOBM Asset ID Sunset Boulevard Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,466,000 119 Sunset Boulevard (Portion of) 123 Sunset Boulevard (Portion of) B 2A Culvert No. 199 / TOBM Asset ID 39th Sideroad Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $953,000 - A 3B Culvert No. 200 / TOBM Asset ID 357516 Christie Beach Road Improve culvert crossing to satisfy design flood frequency criteria and safe access/egress criteria. 3B $418,000 - A+ 4B Culvert No. 201 / TOBM Asset ID 357508 Christie Beach Road Improve culvert crossing to satisfy design flood frequency criteria and safe access/egress criteria. 3B $418,000 - A+ 5A Culvert No. 203 / TOBM Asset ID Christie Beach Road Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $638,000 - A Boulder Channel 6A Culvert No. 185 / TOBM Asset ID Sunset Boulevard Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $552,000 - A Little Beaver River 8A Culvert No. 176 / TOBM Asset ID Georgian Trail Improve culvert crossing to satisfy design flood frequency criteria. 3B $476,000 - A B 9G Culvert No. 178 / TOBM Asset ID Alice Street West Improve Alice Street West culvert and downstream driveway culvert to satisfy design flood frequency criteria. 3B $336,000 - 10A Culvert No. 179 / TOBM Asset ID Baring Street Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $165,000 - A 11A Culvert No. 180 / TOBM Asset ID Alfred Street West Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $201,000 - A 12A Culvert No. 171 / TOBM Asset ID Alice Street West Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,466,000 - B 13A Culvert No. 173 / TOBM Asset ID Napier Street West Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,532,000 - A 14A Culvert No. 174 / TOBM Asset ID Duncan Street West Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,456,000 - A 113A Culvert No. 175 / TOBM Asset ID Alfred Street West Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $2,072,000 - A Elgin Street North 15A Trunk Storm Sewer No. 2 King Street East / Elgin Street North Install trunk storm sewer to resolve overland flow (major system) deficiency 3C $2,386,000 - A Beaver River 17A Storm Sewer Relocation Clark Street /Mary Street Relocate storm infrastructure from private property to municipal road allowance 3A $1,179,000 - B 18A Decommission Historical Flume Clarksburg Decommission historical flume from Clarksburg Mill to prevent Beaver River flood flows from entering storm sewer system 3A $652,000 - B Watercourse 52 20G Culvert No. 147 / TOBM Asset ID Lakeshore Road Improve culvert crossing to maintain conveyance capacity of upstream crossings. 3B $1,877,000 A� 21G Culvert No. 148 / TOBM Asset ID Georgian Trail Improve culvert crossing to maintain conveyance capacity of upstream crossings. 3B $1,086,000 - A 22B Culvert No. 149 / TOBM Asset ID Highway 26 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,874,000 A 23A Culvert No. 150 / TOBM Asset ID Grey Road 2 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $2,303,000 - A 24A Culvert No. 156 / TOBM Asset ID Clark Street Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,272,000 - A+ 25A Culvert No. 151 / TOBM Asset ID 496916 Grey Road 2 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $267,000 - A 26A Culvert No. 152 / TOBM Asset ID Driveway Entrance Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $168,000 A Table 22: Preliminary Preferred Solution Summary ame/ID - Capit- EA Schedule Property Acquisition Watercourse 34 28A Culvert No. 135 / TOBM Asset ID Highway 26 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $3,059,000 208653 Highway 26 (Portion of) B 29A Culvert No. 135A / TOBM Asset ID Highway 26 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,592,000 208663 Highway 26 (Portion of) 208655 Highway 26 (Portion of) B 30A Culvert No. 136 / TOBM Asset ID Georgian Trail Improve culvert crossing to satisfy design flood frequency criteria. 3B $897,000 - A A 31E Culvert No. 137 / TOBM Asset ID Indian Circle Improve culvert crossing to feasible extent within municipal property. 3B $2,798,000 32A Culvert No. 138 / TOBM Asset ID 7th Line Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,886,000 - A Watercourse 32 34A Watercourse Improvements No. 1 Watercourse 34 Improve watercourse and expand floodway to increase conveyance capacity. 3B $3,323,000 135 Hoover Lane B 35A Culvert No. 130 / TOBM Asset ID Highway 26 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $2,040,000 - A Watercourse 31 38E Culvert No. 124 / TOBM Asset ID Hoover Lane Improve culvert crossing to extent possible within municipal road allowance. 3B $1,283,000 A 40A Culvert No. 128 / TOBM Asset ID George McRae Road Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $718,000 - A Outlet 30 42A Culvert No. 121 / TOBM Asset ID Highway 26 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $417,000 - A 43A Culvert No. 122 / TOBM Asset ID Georgian Trail Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $105,000 - A 44A Culvert No. 123 / TOBM Asset ID Old Lakeshore Road Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $383,000 - A Watercourse 28 45A Culvert No. 117 / TOBM Asset ID Old Lakeshore Road Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $599,000 - A Outlet 26 46A Culvert No. 113 / TOBM Asset ID Georgian Trail Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $704,000 - A 47E Culvert No. 114 / TOBM Asset ID Wensley Drive Improve culvert crossing to extent possible without raising road grades. 3B $822,000 B Outlet 25 48A Culvert No. 108/ TOBM Asset ID Delphi Lane Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $988,000 - A Outlet 23 52A Culvert No. 105 / TOBM Asset ID Highway 26 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $204,000 - A Watercourse 21 56A Culvert No. 206 / TOBM Asset ID Highway 26 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $339,000 - A 57A Culvert No. 205 / TOBM Asset ID Georgian Trail Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $128,000 - A 58A Culvert No. 102 / TOBM Asset ID Georgian Trail Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $213,000 - A Watercourse 19 62A Culvert No. 96 / TOBM Asset ID Alta Road Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $2,385,000 - A Watercourse 15 63A Culvert No. 90 / TOBM Asset ID Georgian Trail Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $396,000 - A 114A Trunk Storm Sewer Improvement No. 4 Arrowhead Road Install trunk storm sewer to resolve overland flow (major system) deficiency 3C $1,329,000 - A Table 22: Preliminary Preferred Solution Summary ent Name/ID Location Capit. Watercourse 14 65A Culvert No. 77 / TOBM Asset ID Georgian Trail Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $582,000 - B 66A Culvert No. 78 / TOBM Asset ID Lakeshore Road West Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $636,000 - A 67A Culvert No. 84 / TOBM Asset ID Lakeshore Road West Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $692,000 - A 69A Culvert No. 85 / TOBM Asset ID Blueski George Crescent Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $598,000 - A 70A Culvert No. 87 / TOBM Asset ID Arrowhead Road Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $784,000 - B 71A Culvert No. 88 / TOBM Asset ID Arrowhead Road Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $518,000 - A Watercourse 10 73E Culverts No. 69, 70, 71, 72 / TOBM Asset IDs Lakeshore Road East, Entrances, Georgian Trail Improve culvert crossings and divert additional flow to Outlet 11 and improve Outlet 11. 3B $1,431,000 B B 74G Culvert No. 73 / TOBM Asset ID Grey Road 19 Improve culvert crossing to extent possible within municipal road allowance and improve downstream driveway culvert. 3B $1,472,000 75A SWMF No. 10401 Retrofit / Expansion Alexandra Way Expand and retrofit existing SWMF to improve water quality treatment and peak flow attenuation. 2B $1,978,000 B Watercourse 9 76G Culvert No. 66 / TOBM Asset ID Grey Road 19 Improve Grey Road 19 culvert and downstream driveway culvert to satisfy design flood frequency criteria. 3B $1,248,000 - B Watercourse 7 77E Culvert No. 57 / TOBM Asset ID Grey Road 19 Improve culvert crossing to extent possible within municipal road allowance. 3B $1,437,000 - A Watercourse 6 79E/79A Convey Overflow to Outlet 8 or New Outlet Watercourse 6 Convey overflow to Outlet 8 or construct new outlet to relieve flooding of Watercourse 6 under major storm events. 3B $1,748,000 C 82A Culvert No. 44 / TOBM Asset ID Arlberg Crescent Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,890,000 - A 83A Culvert No. 45 / TOBM Asset ID Brooker Boulevard Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,631,000 - A 84A Culvert No. 46 / TOBM Asset ID Brooker Boulevard Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,816,000 - A 85A Culvert No. 47 / TOBM Asset ID Kandahar Lane Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $800,000 - A 87A Culvert No. 48 / TOBM Asset ID Settlers Way Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $741,000 - A 88A Culvert No. 49 / TOBM Asset ID Settlers Way Path Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $189,000 - A 89E Culvert No. 50 / TOBM Asset ID Heritage Drive Improve culvert crossing to extent possible within municipal road allowance. 3B $455,000 - A 90E Culvert No. 51 / TOBM Asset ID Pioneer Lane Improve culvert crossing to extent possible within municipal road allowance. 3B $734,000 A 91E Culvert No. 52 / TOBM Asset ID Grey Road 19 Improve culvert crossing to extent possible within municipal road allowance. 3B $918,000 A 94 Monterra Road / Watercourse 1 Improvements Monterra Road / Grey Road 21 Improve capacity of Monterra Road roadside ditch and Monterra Road culvert crossing. 3B $1,527,000 B 96A Culvert No. 42 / TOBM Asset ID Monterra Road Improve culvert crossing to satisfy design flood frequency criteria. 3B $915,000 - A Table 22: Preliminary Preferred Solution Summary e .. 'ame/ID Location L••it. Watercourse 1 98E Culvert No. 14 / TOBM Asset ID Grey Road 19 Improve culvert crossing ttpletietotiseiwtide w�rown standard design flood frequency. 3B $1,971,000 - A 99E Culvert No. 15 / TOBM Asset ID Campbell Crescent Improve culvert crossing to level of service less than Town standard design flood frequency. 3B $1,224,000 - A 100A Culvert No. 17 / TOBM Asset ID Gord Canning Drive Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $549,000 - A Silver Creek 104A Culvert No. 28 / TOBM Asset ID Grey Road 19 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $771,000 - A 108E Culvert No. 33 / TOBM Asset ID Trail Crossing Improve culvert crossing to level of service less than Town standard design flood frequency. 3B $224,000 - A 110A Culvert No. 37 / TOBM Asset ID Grey Road 19 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $1,766,000 - A 111A Culvert No. 38 / TOBM Asset ID Grey Road 19 Improve culvert crossing to satisfy design flood frequency criteria (consequently satisfies safe access/egress criteria). 3B $2,138,000 - A 112E Culvert No. 39 / TOBM Asset ID Grey Road 19 Improve culvert crossing to level of service less than Town standard design flood frequency. 3B $1,241,000 - A 116A Culvert No. 36 / TOBM Asset ID Scenic Caves Road Improve culvert crossing to satisfy design flood frequency criteria. 3B $1,008,000 - A IGEORGIAN BAY I N AN I GEORGIAN BAY I TOWN OF COLLINGWOOD LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) EXISTING SWMF RETROFIT (QUANTITY)~ EXISTING SWMF RETROFIT (QUALITY AND ~ QUANTITY) PROPOSED SWMF CREATION (QUALITY)■ PROPOSED SWMF CREATION (QUANTITY)■ ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE (§_) CULVERT ID s SWMF/ LID/ STORAGE AREA ID ■ PRELIMINARY PREFERRED SOLUTION (RECOMMENDED) [}] PRELIMINARY PREFERRED SOLUTION (CONDITIONAL) -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -• BOULDER CHANNEL STUDY AREA -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.45 0.6 Kilometers - ---- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN THIS DRAWING IS SOLELY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEERING LTD . UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHAM ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: BOULDER CHANNEL DRA INAGE IMPROVEMENTS AS SHOWN WERE RECOMMENDED AS PART OF THE LORA BAY DEVELOPMENT SWM POND NO. 1 STORMWATER MANAGEMENT REPORT (TATHAM ENGINEERING LIMITED, DECEMBER 2021). ADDITIONAL DRAINAGE IMPROVEMENTS IN THE LORA BAY DEVELOPMENT LANDS WILL BE DEVELOPED AS PART OF THE MASTER DEVELOPMENT PLAN FOR THESE LANDS No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER PLAN (60% SUBMISSION) SEPT 2022 PRELIMINARY PREFERRED SOLUTIONS MAP DESIGN: JM FILE: 121076 DWG: BADRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1:5000 N A N I GEORGIAN BAY I BLUE MOUNTAIN TOWN OF VILLAGE CO LLINGWOOD IGEORGIAN BAY I LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) EXISTING SWMF RETROFIT (QUANTITY)~ THORNBURY WEST DRAINAGE MASTER EXISTING SWMF RETROFIT (QUALITY AND PLAN IMPROVMENTS AREA (SEE NOTE) ~ QUANTITY) PROPOSED SWMF CREATION (QUALITY)■ PROPOSED SWMF CREATION (QUANTITY)■ ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE (§_) CULVERT ID s SWMF/ LID/ STORAGE AREA ID ■ PRELIMINARY PREFERRED SOLUTION (RECOMMENDED) [}] PRELIMINARY PREFERRED SOLUTION (CONDITIONAL) -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -• THORNBURY WEST END DRAINAGE STUDY AREA -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.45 0.6 Kilometers DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN T HI S DRAW ING IS SOLELY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEER ING LTD . UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN T HAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, R E PRODUCED ELECTRONICALLY STORED OR TRANSMITT ED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: D RAINAGE IMPROVEMENTS IN THORNBURY WEST END STUDY AREA RECOMMENDED THROUGH THORNBURY WEST DRAINAGE MASTER PLAN MUNICIPAL CLASS EA (TATHAM ENGINEER ING LIMITED, MARCH 2019) No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER P LAN (60% SUBMISSION) SEPT 2022 PRELIMINARY PREFERRED SOLUTIONS MAP DESIGN: JM FILE: 121076 DWG: 8BDRAWN: KKS DATE: JUL. 2022 CHECK· ORT SCALE 1 :5000 N Atv I GEORGIAN BAY I 11;.,,, nn.: LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) EXISTING SWMF RETROFIT (QUANTITY)~ EXISTING SWMF RETROFIT (QUALITY AND ~ QUANTITY) PROPOSED SWMF CREATION (QUALITY)■ PROPOSED SWMF CREATION (QUANTITY)■ PROPOSED SWMF CREATION (QUALITY AND ■ QUANTITY) PROPOSED CENTRALIZED LID■ PROPOSED EXPANSION OF FLOODPLAIN■ STORAGE @ CULVERT ID 8 SWMF/ LID/ STORAGE AREA ID ■ PRELIMINARY PREFERRED SOLUTION (RECOMMENDED) [}] PRELIMINARY PREFERRED SOLUTION (CONDITIONAL) -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -• THORNBURY WEST END DRAINAGE STUDY AREA -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.6 Kilometers ------- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN THIS DRAWING IS SOLE LY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEERING LT D. UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: D RAINAGE IMPROVEMENTS IN THORNBURY WEST END STUDY AREA RECOMMENDED THROUGH THORNBURY WEST DRAINAGE MASTER PLAN MUNICIPAL CLASS EA (TATHAM ENGINEER ING LIMITED, MARCH 2019) No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER P LAN (60% SUBMISSION) SEPT 2022 PRELIMINARY PREFERRED SOLUTIONS MAP DESIGN : JM FILE: 121076 DWG: BCDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1 :5000 IGEORGIAN BAY I N A N I GEORGIAN BAY I TOWN OF COLLINGWOOD LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) [izj EXISTING SWMF RETROFIT (QUANTITY) [izj EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @) CULVERT ID s SWMF/ LID/ STORAGE AREA ID ■ PRELIMINARY PREFERRED SOLUTION (RECOMMENDED) [2J PRELIMINARY PREFERRED SOLUTION (CONDITIONAL) -• WATERCOURSE IMPROVEMENT -• OVERLAND FLOW ROUTE IMPROVEMENT -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.6 Kilometers ------- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN T HIS DRAWING IS SOLE LY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEER ING LT D. UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER PLAN (60% SUBMISSION) SEPT 2022 PRELIMINARY PREFERRED SOLUTIONS MAP DESIGN : JM FILE: 121076 DWG: 8DDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1 :5000 LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT - • PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) ~ EXISTING SWMF RETROFIT (QUANTITY) ~ EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @') CULVERT ID 8 SWMF/ LID/ STORAGE AREA ID ■ PRELIMINARY PREFERRED SOLUTION (RECOMMENDED) 0 PRELIMINARY PREFERRED SOLUTION (CONDITIONAL) -• WATERCOURSE IMPROVEMENT -• OVERLAND FLOW ROUTE IMPROVEMENT -• DRAINAGE ACT IMPROVEMENT AREA -WATERCOURSE ~ SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION a'.: ' --' N u.J ~ ::::, IGEORGIAN BAY I NOW p 0 0. 07 0. 15 0 .3 ------ I GEORGIAN BAY I 0.45- N A 0 .6 Kilometers DISCLAMER AND COPYRIGHT THE IN FORMAT ION CONTA INED IN T HIS DRAW IN G IS SOLELY FO R THE USE O F T HE TOWN OF THE BLUE MOUNTA INS FOR T HE PU RPOSE FO R W HI C H IT HAS BEEN P REPA RED AND TATHAM EN GINEER ING LTD . UNDE RTAKES NO DUTY O R ACCE PT S A NY RES PO NSIBILI T Y TO A NY T H IR D PART Y WHO M AY R ELY UPO N T HIS DRAWI NG. T HI S D RAW IN G MAY NOT B E U SED FO R ANY P URPO SE OTHER T HA N T HAT PR OV ID ED IN THE CO NT RAC T BET W EEN THE T OW N OF T HE B L U E MO U NTAINS A N D TAT HAM EN GI N E E RING LT D NOR MAY A N Y D E TAIL OR EL EMENT O F TH IS D RAWI N G B E R EMOV E D, R E P RODUCE D EL ECTR ONICALLY STOR ED O R T RA N SM ITT E D IN ANY FO R M W IT HO UT TH E E X PRE S S W RITTE N CO NSEN T OF THE T OW N OF THE BLU E MOU NTA INS NOTE: D RAINAGE IMPROV E M ENTS IN THE PAR K BRI D G E , E DEN OA K AN D MACPH ERSO N LA ND S R ECOM ME ND E D THR O UG H T H E R E G IONAL STO RM WAT ER MANA GE MENT P LAN -BL U E M OU NTA IN DI V ERS IO N DRAIN -DRAIN A GE ACT A SSESS M ENT REPORT (WT INFRASTRUCTURE, M A RCH 2022). No. REVISION DES CRIPTION DATE E NG IN EERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAND RA INAGE M ASTE R P L A N (60% S UB M ISS IO N ) SEP T 2022 PRELIMINARY PREFERRED SOLUTIONS MAP DES IGN: J M F ILE: 1 21 0 76 DWG: SEDRAW N: KKS DATE: JU L. 2022 C HECK· DRT S C ALE 1 :500 0 DRAINAGE ACT IMPROVMENT AREA (SEE NOTE) GEORGIAN BAY N A I GEORGIAN BAY I LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT -• PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) ~ EXISTING SWMF RETROFIT (QUANTITY) ~ EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @ CULVERT ID s SWMF/ LID/ STORAGE AREA ID ■ PRELIMINARY PREFERRED SOLUTION (RECOMMENDED) [}] PRELIMINARY PREFERRED SOLUTION (CONDITIONAL) -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -• DRAINAGE ACT IMPROVEMENT AREA -WATERCOURSE = SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.45 0.6 Kilometers ------- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN THIS DRAWING IS SOLE LY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEERING LT D. UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: DRAINAGE IMPROVEMENTS IN THE PARKBRIDGE , EDEN OAK AND MACPHERSON LANDS RECOMMENDED THROUGH THE REGIONAL STORMWATER MANAGEMENT PLAN -BLUE MOUNTAIN DIVERSION DRAIN -DRAINAGE ACT ASSESSMENT REPORT (WT INFRASTRUCTURE, MARCH 2022) . No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLANDRAINAGE MASTER P LAN (60% SUBMISSION) SEPT 2022 PRELIMINARY PREFERRED SOLUTIONS MAP DESIGN : JM FILE: 121076 DWG: BFDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1 :5000 . • • • • • • •• 4 ••••.. • • •• •• ' '·•C •••., '. •' .~ -. ...• ., N A I GEORGIAN BAY I LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT -• PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) ~ EXISTING SWMF RETROFIT (QUANTITY) ~ EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @ CULVERT ID s SWMF/ LID/ STORAGE AREA ID ■ PRELIMINARY PREFERRED SOLUTION (RECOMMENDED) [}] PRELIMINARY PREFERRED SOLUTION (CONDITIONAL) -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -WATERCOURSE ~ SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0.3 0.6 Kilometers ------- DISCLAMER AND COPYRIGHT THE INFORMATION CONTAINED IN THIS DRAWING IS SOLE LY FOR THE USE OF THE TOWN OF THE BLUE MOUNTAINS FOR THE PURPOSE FOR WHICH IT HAS BEEN PREPARED AND TATHAM ENGINEERING LT D. UNDERTAKES NO DUTY OR ACCEPTS ANY RESPONSIBILITY TO ANY THIRD PARTY WHO MAY RELY UPON THIS DRAWING. THIS DRAWING MAY NOT BE USED FOR ANY PURPOSE OTHER THAN THAT PROVIDED IN THE CONTRACT BETWEEN THE TOWN OF THE BLUE MO UNTAINS AND TATHA M ENGINEERING LTD NOR MAY ANY DETAIL OR ELEMENT OF TH IS DRAWING BE REMOVED, REPRODUCED ELECTRONICALLY STORED OR TRANSMITTED IN ANY FORM WITHOUT THE EXPRESS WRITTEN CONSENT OF THE TOWN OF THE BLUE MOUNTAINS NOTE: No. REVISION DESCRIPTION DATE ENGINEERS STAMP TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRAINAGE MASTER PLAN (60% SUBMISSION) SEPT 2022 PRELIMINARY PREFERRED SOLUTIONS MAP DESIGN : JM FILE: 121076 DWG: BGDRAWN: KKS DATE: JUL. 2022 CHECK· DRT SCALE 1:5000 N A I GEORGIA N BAY I TH ORN BU RY \ ,. K_EY PLAN LEGEND -EXISTING CULVERT -CULVERT IMPROVEMENT -• PROPOSED TRUNK STORM SEWER ~ EXISTING SWMF --EXISTING STORM SEWER • EXISTING MAINTENANCE HOLE ~ EXISTING SWMF RETROFIT (QUALITY) ~ EXISTING SWMF RETROFIT (QUANTITY) ~ EXISTING SWMF RETROFIT (QUALITY AND QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY) ■ PROPOSED SWMF CREATION (QUANTITY) ■ PROPOSED SWMF CREATION (QUALITY AND QUANTITY) ■ PROPOSED CENTRALIZED LID ■ PROPOSED EXPANSION OF FLOODPLAIN STORAGE @ CULVERT ID s SWMF/ LID/ STORAGE AREA ID ■ PRELIMINARY PREFERRED SOLUTION (RECOMMENDED) [}] PRELIMINARY PREFERRED SOLUTION (CONDITIONAL) -• WATERCOURSE IMPROVEMENT --OVERLAND FLOW ROUTE IMPROVEMENT -WATERCOURSE ~ SETTLEMENT AREA BOUNDARY --EXISTING INFRASTRUCTURE RELOCATION 0 0.07 0.15 0. 3 0.6 Kilometers ------- DISCLAMER AND COPYRIGHT T HE IN FORMAT ION CONTA INED IN T HI S DRAW IN G IS SO LELY FO R T H E USE O F T HE TOW N O F THE BLUE MOUNTA IN S FOR T HE PU RPOSE FO R W HI C H IT HAS BEEN P REPA RED A N D TATHAM EN GI N EER ING LTD . UNDE RTAKES NO DUTY O R ACCE PT S A NY RES PO NSIBILI T Y TO A NY T H IR D PART Y WHO M AY R ELY UPO N T HIS DRAWI NG. T HI S D RAW IN G MAY NOT B E USED F OR ANY PURPO SE OTHER T HA N T HAT PR OV ID ED IN THE CO NT RAC T BET W EEN THE T OW N OF T HE B L U E MO U NTAINS A N D TAT HAM E NGI N E E RING LT D NOR MAY A N Y D E TAIL OR E L EMENT O F TH IS D RAWI N G B E R EMOV E D, R E P RODUCE D EL ECTR ONICALLY ST OR ED O R T RA N SM ITT E D IN ANY FO R M WIT H OUT TH E E X PRE SS W RITTE N CO NSEN T OF THE T OW N OF THE BLU E MOU NTA INS NOTE: No. REVISION DES CRIPTION DATE ENG IN EERS STAM P TOWN OF THE BLUE MOUNTAINS DRAINAGE MASTER PLAN ~r TATHAM ENGINEERING DRA INAGE MASTER PLAN (60% S UBM ISS ION) SE PT 2022 PRELIMINARY PREFERRED SOLUTIONS MAP DES IGN: JM FILE: 121076 DWG: SHDRAWN: KKS DATE: JU L. 2022 CHECK· DRT SCALE 1:50 00 10.3 SUMMARY OF PRELIMINARY PREFERRED SOLUTIONS The costs of the general recommendations and induvial projects recommended as part of the preliminary preferred solution developed through this Drainage Master Plan are summarized in Table 23. Table 23: Project Costs Summary – Preliminary Preferred Solution PROJECT COST ITEM COST General Recommendations Alternative 2D – Lot Level Low Impact Development Measures $0 Alternative 2E – Linear Low Impact Development Measures $25,906,0001 Alternative 2G – Mechanical Treatment Devices $9,945,0002 Alternative 3A – Minor Drainage System Improvements $8,246,0003 Alternative 3D – Drainage Outlets Design, Operation and Maintenance $60,0004 Alternative 3E – Drainage System Operation and Maintenance $157,0005 Subtotal General Recommendations $18,408,000 - $34,369,000 Individual Drainage Projects Alternative 2B - Retrofit/New Stormwater Management Facilities for Quality Control $1,978,000 Alternative 3A – Minor Drainage System Improvements $1,831,000 Alternative 3B – Culvert/Watercourse Major Drainage System Improvements $79,929,000 Alternative 3C – Trunk Storm Sewer/Overland Flow Route Major System Improvements $3,715,000 Subtotal Individual Drainage Projects $87,453,000 Total $105,861,000 - $121,822,000 1. Cost assumes full implementation of Linear LIDs on all eligible roads in the study area. 2. Cost assumes full implementation of Mechanical treatment devices for all eligible storm sewer systems in the study area which are currently untreated. 3. Cost shown is difference between cost to improve storm sewers to satisfy town standards and cost to replace existing storm sewers at current sizes. 4. Cost includes design standards update and one year of operation and maintenance costs. 5. Cost includes one year of operation and maintenance costs. The range of costs shown under the Subtotal General Recommendation represents the difference in costs if the Town were to implement the full scope of Alternative 2G and no scope of Alternative 2E opposed to the cost if the Town were to implement the full scope of Alternative 2E and no scope of Alternative 2G to provide water quality treatment. To implement the preferred solution, a number of properties or portions thereof have been identified for acquisition by the Town. The properties recommended for acquisition under the preferred solution are summarized in Table 24. Table 24: Property Acquisition Summary – Preliminary Preferred Solution PROJECT ADDRESS Recommended Property Acquisition 1 119 Sunset Boulevard (Portion of) 123 Sunset Boulevard (Portion of) 28 208653 Highway 26 (Portion of) 29 208663 Highway 26 (Portion of) 208655 Highway 26 (Portion of) 34 135 Hoover Lane Conditional Property Acquisition 79 209741 Highway 26 (Portion of) 11 Next Steps 11.1 PUBLIC CONSULTATION - PUBLIC INFORMATION CENTRE (PIC #2) A second Public Information Centre (PIC) will be held to present the preliminary preferred alternative solutions to the identified drainage issues in the study area including the list of individual projects identified under each preliminary preferred alternative solution. Attendees will be encouraged to provide input / feedback regarding the study and the preliminary preferred alternative solutions presented. Comment sheets will be provided and attendees will be encouraged to identify their preferences regarding the alternative design solutions. Prior to the PIC, this Draft Environmental Assessment document will be made available for public review at the Town of The Blue Mountains Town Hall. The document will also be made accessible via the project webpage. Also, a notification letter will be distributed to local res idents and stakeholders presenting the alternative drainage solutions and notifying them of the PIC. The notification will include a copy of the PIC comment sheet to provide everyone with an opportunity to provide input / comments regarding the study. Following the conclusion of PIC #2, the public feedback will be taken into account and the evaluation completed to identify the preliminary preferred solutions will be updated accordingly. After updating the evaluation, the preferred solutions will be finalized. 11.2 IMPLEMENTATION PLAN After finalization of the preferred solutions, an implementation plan will be developed for the construction of new and rehabilitation of old infrastructure. A 10-year capital plan will be developed based on project prioritization, and in consideration of the Town’s capital budget, the DC eligible costs, the Town’s current and future capital projects, planned development, and the project cost estimates. Development of the implementation plan is described in the following sections. Project Prioritization / Forecasting The individual projects identified as part of the preferred solution(s) will be prioritized in order of importance through an impact and risk assessment. Specifically, a probability of failure will be assigned to each project based on the frequency of occurrence. Also, the economic, social and environmental consequence of failure will be evaluated for each project. The projects will be prioritized based on impact and risk as well in consideration of the Town’s cu rrent capital plans, neighbourhood renewal programs and road improvements. We will provide recommendations regarding the timing of the individual projects for a 10 -year span based on project prioritization and in consideration of the Town’s capital budget, the DC eligible costs, the Town’s current and future capital projects, planned development, and the project cost estimates. DC Eligibility / Funding Review The proposed drainage improvements will be reviewed in conjunction with the future land use conditions to identify opportunities for the Town to apply development charges to contribute to the cost of proposed drainage improvements supporting future development. The differences in project costs to address existing and future condition drainage deficien cies will be considered the DC eligible costs for each project. As part of this review, additional sources of funding for the drainage projects will also be identified and evaluated, including special levies and stormwater utilities. Master Drainage Report (90%) The Draft Master Drainage Report (60%) will be expanded to summarize the implementation plan, including the project prioritization, forecasting, DC eligibility, funding review and approval / permitting requirements, recommended. The Draft Master Drainage Report (90%) will be submitted to the Town for review and approval. Implementation Program An implementation program will be developed to identify the phasing, financing, operations and monitoring requirements for construction of the preferred solution(s) and development. The implementation program will outline the parties responsible to complete the works, timing for construction, recommendations for subsequent studies, operation and maintenance requirements, monitoring programs, and timeframes for updates to the Master Drainage Plan and implementation plan. 11.3 POLICY FRAMEWORK Consultation with the Town and CA staff will be completed to help guide development of a policy framework regarding the management of stormwater in existing and future growth areas as part of the preparation of the Drainage Master Plan for incorporation into the Town’s Official Plan. This will include a review and evaluation of existing design criteria, drainage deficiencies, Source Water Protection requirements, proposed land uses, redevelopment and intensification, and current policies. 11.4 MASTER DRAINAGE REPORT (100%) Following development of the policy framework, the Master Drainage Report (90%) will be updated to summarize the policy framework. The Master Drainage Report (100%) will be submitted to the Town for review and approval. Appendix A: Existing Conditions Report Appendix B: Background Appendix C: Fluvial Geomorphology Study Appendix D: Natural Heritage Study Appendix E: Stage 1 Archaeological Assessment Appendix F: Future Conditions Analysis Appendix G: Public Information Centre 1 Appendix H: Conceptual Design Drawings Appendix I: LID Design Drawings and Analytical Results Appendix J: Construction Cost Estimates Appendix K: Alternative Solutions Digital Model Files