Public Information Centre No. 2

Transcription

1 Public Information Centre No. 2 Stoney Creek and Battlefield Creek Flood and Erosion Control Project East Escarpment Watershed Restoration Program Conservation Ontario Class Environmental Assessment Date: November 28, 2017 / Location: Croatian Community Centre / Time: 6:00 p.m. to 8:00 p.m. Preliminary Preferred Solution

2 Study Area The Study area includes the erosionprone Lower Stoney Creek and Battlefield Creek watersheds as well as the vast headwater above the escarpment. ESCARPMENT UPPER WATERSHEDS

3 Project Overview Study Background and Purpose In 2011, the Hamilton Conservation Authority (HCA) and the City of Hamilton prepared a Class Environmental Assessment (EA) for the Lower Stoney Creek and Lower Battlefield Creek (sections of the watershed below the escarpment) which identified areas that were susceptible to flooding and erosion. As part of that study, the feasibility of storage based solutions located above the escarpment to address flood and erosion risk in the lower reaches was assessed and considered for further study.

4 Project Overview Study Goal In 2015, the HCA released a Discussion Paper entitled East Escarpment Conservation Area which expressed the goal: To create a new conservation area in the east end of the City of Hamilton, specifically the Upper Stoney Creek and Upper Battlefield Creek watersheds above the Escarpment to provide natural hazard attenuation, natural heritage enhancements and recreation opportunities.

5 Project Overview Study Objectives To utilize the floodplain areas of Upper Battlefield and Upper Stoney Creeks to retain water to provide flood attenuation to reduce flood and erosion risks both above and below the Niagara Escarpment. To enhance and enlarge existing wetland areas and to create new wetland areas to provide enhanced wetland hydrologic function to reduce the impacts of high water events and provide water to area watercourses during low flow periods. To restore the natural features and functions of the watercourses in the subject area. To restore, enhance and enlarge the natural heritage features associated with the floodplains, wetlands and watercourses of the area.

6 Conservation Ontario Class EA Approach This study follows the process outlined in: Conservation Ontario's Class Environmental Assessment for Remedial Flood and Erosion Control Projects The process provides a project planning and design framework for proponents (Conservation Authorities like Hamilton Conservation Authority) to ensure they meet the requirements of the Provincial Environmental Assessment Act. Consultation is required with all stakeholders including the public and agency partners at all stages. Initiate Class EA Issue Notice of Intent We are here Prepare Baseline Environmental Inventory Evaluate Alternative Remedial Measures and Select Preferred Alternative Conduct Detailed Analysis of Environmental Impact Environmental Study Report

7 Problem and Opportunity Statement The 2011 Class EA identified significant portions of the Lower Stoney Creek and Battlefield Creeks as being susceptible to flood and erosion risk. HCA has set a goal of creating a new conservation area in the Upper Stoney Creek and Upper Battlefield Creek watershed. Through detailed study and consultation, opportunities to provide flood and erosion impact management, through attenuation of runoff in existing and enhanced wetland areas above the Escarpment, have been assessed and evaluated. These areas and locations for runoff storage would ultimately have the potential to become multi-use public spaces as part of a new conservation area.

8 Flood and Erosion Control Alternatives In 2011, the Hamilton Conservation Authority (HCA) and the City of Hamilton prepared a Class Environmental Assessment (EA) for the Lower Stoney Creek and Lower Battlefield Creek. Alternatives considered for flood mitigation included: 1. Flow conveyance upgrades (channels, floodplains, culverts and bridges) 2. Roadway profiles adjustments to reduce flooding 3. Flood proofing of buildings 4. Elimination/reduction of culvert blockages 5. Off-line and/or on-line flood storage systems Alternatives considered for erosion mitigation included: 1. Local creek protection works to address/ prevent erosion 2. Reach-scale channel works 3. Off-line and/or online erosion storage systems The flood and erosion control alternatives considered directly as part of this Class EA are online flood and erosion storage systems.

9 Approaches for Flood and Erosion Control Storage Systems 1. Raise Roadways / Modify and Optimize Culvert Geometry (on-line storage) 2. Repurpose existing wetland systems (on-line / off-line storage) 3. Excavate storage areas and creating holding areas (off-line storage) 4. Combinations of off-line / on-line storage 1970 Fenco Flood and Erosion Control Study Constructed Wetland System (City of London Dingman Creek wetland)

10 Potential Locations for Flood and Erosion Control Storage Systems

11 Alternatives have been evaluated considering four environmental categories and various evaluation criteria specifically relevant to the study area, objectives and stakeholders: Category Criteria Functional Environment Effectiveness of flooding and erosion mitigation Constructability Natural Environment Impacts/opportunities related to terrestrial ecology and fisheries Social Environment Impacts/opportunities related to public use, safety, adjacent properties and structures, land use and recreation Economic Environment Land Costs Capital and maintenance cost for the storage systems

12 Evaluation/ Screening of Potential Storage Sites Evaluation Category Functional Natural Social Economic Evaluation Criteria Effectiveness of Flooding Mitigation Effectiveness of Erosion Mitigation Battlefield Stoney Creek Sites Creek Site BC-1 SC-1 SC-2 SC-3 SC-4 SC-5 SC-6 SC-7 SC-8 X X X X X X X X X Constructability X X X X X X Terrestrial Ecology Impacts/Opportunities Fisheries Impacts/Opportunities Public Use Impacts/Opportunities X X X Safety Impacts/ Opportunities X Adjacent Property Impacts/Opportunities Land Use Impacts/Opportunities Recreation Impacts/Opportunities Legend: Negative: X, Positive: Not Carried Forward X X X X X X X X X X Land Costs X X X X X X Capital Costs X X X X Maintenance Costs X X X X X X Carry Forward (Yes/No) X X X X X Carried Forward

13 Preliminary Preferred Flood and Erosion Control Storage Systems Battlefield Creek Site 1 (BC-1): Significant erosion and flood control storage potential Hamilton Conservation Authority controlled lands Significant opportunity for terrestrial ecology and fishery habitat enhancements Stoney Creek Site 5 (SC-5): Significant erosion and flood control storage potential Partially Hamilton Conservation Authority controlled lands Significant opportunity for terrestrial ecology enhancements Significant opportunity for public recreational use Stoney Creek Site 7 (SC-7): Moderate erosion and flood control storage potential Moderate opportunity for terrestrial ecology enhancements Significant opportunity for public recreational use Stoney Creek Site 8 (SC-8): Low to moderate erosion and flood control storage potential Significant opportunity for terrestrial ecology enhancements Moderate opportunity for public recreational use

14 Preliminary Preferred Flood and Erosion Control Storage Systems

15 Summary of Results for Preliminary Preferred Flood and Erosion Control Systems Four (4) flood and erosion control sites: BC-1, SC-5, SC-7 and SC-8; each would allow for wetland creation, terrestrial and fishery habitat improvements and public recreational usage Reduced downstream property and building flooding for all storms up to and including the 100 year event Duration of erosive flows reduced by 32% and 27% for Battlefield Creek and Stoney Creek respectively Properties and Buildings Removed from Risk Scenario Storm Event: 2 Year 5 Year 10 Year 25 Year 50 Year 100 Year Regional Storm Existing Properties With Flood Control Systems Removed from Risk Existing Buildings With Flood Control Systems Removed from Risk

16 Implementation of Flood and Erosion Control Storage Systems Implementation considerations and process: Topographic survey of lands Mapping of terrestrial habitats, including species at risk Mammal and amphibian inventories Fisheries habitat mapping Groundwater, soils and bedrock detailed assessment Cultural heritage and Archaeological assessments Design storage system layout and grading, including modified road profile and berming Design storage system outlet culvert (s), flow control structures Determine potential impacts to adjacent lands and establish mitigating measures Design wetland and terrestrial habitat enhancements Design trail systems, boardwalks, parking, servicing and recreational land uses Determine staging

17 Implementation of Flood and Erosion Control Storage Systems Implementation would include detailed assessment of depth to bedrock within the preferred flood and erosion control storage systems.

18 Next Steps Receive public comments by December 22, 2017 Incorporate public and agency input into alternative assessment Select preferred solution and implementation method Prepare and file Class Environmental Assessment Report

19 We Would Like To Hear From You Please complete the comment sheet and place in the Comment Box or send your comments by /fax/letter to either of the following Project Team members by December 22, You can view tonight s information boards on our website: Hamilton Conservation Authority Mr. Scott Peck, MCIP, RPP Deputy Chief Administrative Officer/ Director Watershed Planning & Engineering 838 Mineral Springs Road Ancaster ON L9G 4X1 Tel: ext tspeck@conservationhamilton.ca Amec Foster Wheeler Environment & Infrastructure Mr. Ron Scheckenberger, M.Eng., P.Eng. Project Manager 3450 Harvester Road, Unit 100 Burlington ON L7N 3W5 Tel: ron.scheckenberger@amecfw.com Thank you for your participation