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Hydrology & Surface Water - Lakeshore East Joint Corridor

← Return to Early Works: Lakeshore East Joint Corridor

Key Findings

  • The project footprint is partly located within the Toronto and Region Conservation Authority’s (TRCA) regulated area and the Don River floodplain.
  • Detailed floodplain impact assessment will be conducted as design and planning progress, in consultation with TRCA, Waterfront Toronto and the City of Toronto to ensure no negative impacts on floodplain conditions and adjacent projects/flood protection initiatives.
  • Stormwater management design will consider guidance provided by the Ministry of the Environment, Conservation and Parks Stormwater Management Planning and Design Manual, Ontario Ministry of Transportation Drainage Management Manual, Toronto and Region Conservation Authority Stormwater Management Criteria, and the Low Impact Development Stormwater Management Planning and Design Guide Toronto and Region Conservation Authority/Credit Valley Conservation as required.

Lakeshore East Joint Corridor Hydrology & Surface Water Study Area

Potential Effects & Mitigation Measures

Potential Effects:

  • Potential impact on flooding conditions in the Don River floodplain.
  • Potential flooding impacts on site during construction.
  • Potential change in stormwater quantity and quality due to potential erosion of exposed soil and increased sediment loading which may impact receiving water bodies and/or municipal stormwater drainage system.

Mitigation Measures:

  • Floodplain impact assessment will be conducted during detailed design following Toronto and Region Conservation Authority (TRCA) guidelines once relevant design information is available.
  • Develop a flood contingency plan with specific measures for any proposed work or temporary laydown and staging areas in the Don River floodplain, as project planning progresses.
  • Develop the overall stormwater quality and quantity control strategy in accordance with all relevant municipal, provincial, and federal requirements.
  • Develop a stormwater management plan and an erosion and sediment control plan, as project planning progresses.
  • The following stormwater management best practices will be considered and implemented as required:
    • reduce amount of exposed soil;
    • install sediment control measures before grading/land alterations begin;
    • sequence early works activities;
    • protect storm drain inlets to filter out debris; and
    • stabilize all exposed soil areas as soon as land alterations are complete.
  • If required, obtain a Municipal Discharge Permit (City of Toronto Private Water Discharge Permit/Agreement) to manage excess surface water/stormwater.
  • TRCA, Waterfront Toronto, and City of Toronto will be consulted to avoid potential infrastructure conflicts and impacts to adjacent flood protection measures/ initiatives.

Example of silt fencing used for erosion and sediment control.

Example of silt fencing used for erosion and sediment control.
Source: Metrolinx, 2020.

← Return to Early Works: Lakeshore East Joint Corridor

Submissions are closed.