Sustainable Technologies Evaluation Program (STEP)

The multi-agency Sustainable Technologies Evaluation Program (STEP) carries out significant work relating to stormwater management throughout the Toronto and Region Area of Concern.


The key water focus areas within STEP include:


green roof

STEP’s water focus areas include low impact development (LID) practices such as green roofs.



Rural Clean Water Program

The Rural Clean Water Program improves water quality by partnering with agricultural and rural communities to reduce water contamination on farm and rural lands by reducing bacteria, nutrient and phosphorus loading to watercourses and ultimately to Lake Ontario.


greenhouse at McVean Farm



Wet Weather Flows in the City of Toronto

The City of Toronto has made significant progress in implementing the Wet Weather Flow Master Plan (WWFMP), which is a priority action identified for the Toronto and Region Remedial Action Plan.


Since the adoption of WWFMP by city council in 2003, the city has invested approximately $485 million in wet weather flow management projects to improve water quality in Toronto’s watercourses and Lake Ontarioshoreline, build resilience to reduce basement flooding risks associated with extreme storms and carry out projects to restore and protect watercourses from future erosion, which supports ecosystem health.


Toronto Water’s 10-Year Capital Plan (2016–2025) identifies almost $2.8 billion for the implementation of WWFMP projects over the next 10 years.



The City of Toronto is building a new 3 km outfall for the Ashbridges Bay Wastewater Treatment Plant (ABTP). The project is currently under design.


Once constructed, it will provide full hydraulic capacity for all treated and bypass flows from the facility and eliminate near shoreline discharges from the ABTP, and will improve the trophic state of waters in the nearshore zone adjacent to Ashbridges Bay.


Ashbridges Bay Wastewater Treatment Plant

Ashbridges Bay Wastewater Treatment Plant



Discharges from combined sewer overflows (CSOs) and stormwater discharges have been identified as the principal sources of pollution leading to the designation of Toronto and Region as an Area of Concern.


The City of Toronto is currently implementing the Don and Central Waterfront Project – an integrated system of wet weather flow tunnels, storage and treatment facilities to address CSOs and polluted stormwater discharges. Once fully implemented, the project will:

  • Significantly improve water quality in the Don River and Central Waterfront
  • Enhance recreational uses of the waterfront
  • Improve aquatic habitat for fish and wildlife
  • Reduce nutrient levels that cause excessive algae growth
  • Support revitalization efforts along the Central Waterfront
  • Help the City meet provincial requirements for controlling combined sewer overflows
  • Bring us closer to delisting Toronto and Region as a Great Lakes Area of Concern


Toronto central waterfront at sunrise

Central Waterfront



As part of the Wet Weather Flow Master Plan, the City of Toronto began a program in 2005 to identify sewer outfalls with sanitary cross-connections. The program was designed to identify all contaminated flows from storm sewers and to initiate remedial actions to eliminate these flows.


As of December 2014, a total of 695 cross-connections had been identified, of which 91% have been corrected. This has led to the delisting of 113 “priority outfalls” – outfalls that are known to have intermittent yet frequent contaminated discharge.



The efforts being made by municipalities to improve the management of stormwater and eliminate combined sewer overflows are the key actions that will continue to improve water quality at Toronto’s beaches over time. Actions to eliminate dry weather flows will also reduce bacterial loadings to the waterfront. The Toronto Beaches Plan, which includes public education initiatives, waterfowl roundup and relocation, egg oiling, and improved operations and maintenance initiatives (such as improved litter pickup and waste collection, and beach grooming) have contributed to improved beach water quality.


In 2016, eight of Toronto’s 11 beaches were certified Blue Flag beaches. The Blue Flag status reflects their high standards for water quality, along with other factors such as environmental education, environmental management, safety, and services.


aerial view of Toronto Beaches