Item - 2023.IE4.6

The Infrastructure and Environment Committee:

1. Received the report (May 23, 2023)  from the General Manager, Toronto Water for information.

Adopted in 2003, the Wet Weather Flow Master Plan provides planning for many initiatives that reduces the adverse impacts of stormwater (rain and melted snow) on the City's environment within a multi-year implementation horizon.  This purpose of this report is to provide Council with an update of the progress of key Wet Weather Flow Master Plan initiatives since the last Wet Weather Flow Master Plan update in 2017. 

Key objectives of the Wet Weather Flow Master Plan include improving water quality along the waterfront, beaches and watercourses, protection of vulnerable City sewer and water infrastructure from erosion and reducing the risk of flooding to private and City properties during extreme wet weather. The Wet Weather Flow Master Plan also provides guidance on municipal operations, environmental monitoring and public education initiatives related to stormwater management.

Significant progress has been made on critical Wet Weather Flow Master Plan initiatives, most notably, construction of the Don River and Central Waterfront Project which is the largest and most significant stormwater management program in the city’s history, the Basement Flooding Protection Program, the rehabilitation of City stormwater management facilities, and in implementation of works within the watercourse and shoreline management programs.  Policy updates to guide stormwater management for development and redevelopment have also been initiated.

Challenges due to construction cost escalation, constrained engineering and technical resources and competing commitments have impacted the implementation of the Wet Weather Flow Master Plan, however key initiatives such as the construction of the Don River and Central Waterfront Project (and related projects - the Integrated Pumping Station and the High Rate Treatment Facility at the Ashbridges Bay Treatment Plant), critical end-of pipe projects and Basement Flooding Protection Program projects remain top priorities.

Implementation of the Wet Weather Flow Master Plan is funded by investments set out in Toronto Water’s annual capital budget and is primarily funded by the water rate with supplementary contributions from Development Charges, and federal funding through the Disaster Mitigation Adaptation Fund.