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Hydrology & Surface Water - East Harbour Station

← Return to Early Works: East Harbour Station Draft Report

Key Findings

  • The project footprint is partly located within the Toronto and Region Conservation Authority’s (TRCA) Regulation Area and the Don River floodplain.
  • Detailed floodplain impact assessment will be conducted as design and planning progress, in accordance with TRCA guidelines and 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.
  • East Harbour Station early works activities will consider and be coordinated with the Don Mouth Naturalization and Port Lands Flood Protection Project, Lower Don River West Remedial Flood Protection Project, Broadview and Eastern Flood Protection Municipal Class Environmental Assessment and/or other adjacent projects as required.
  • TRCA will be consulted to align East Harbour Station early works with Lower Don Special Policy Area requirements, including the approach to floodproofing and flood modeling requirements.

East Harbour Station 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 which may impact receiving waterbodies and/or municipal stormwater drainage systems.

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.
  • East Harbour Station early works will be aligned with the Lower Don Special Policy Area requirements, in consultation with TRCA.

← Return to Early Works: East Harbour Station Draft Report