Toronto and region: Area of Concern
The contributions of federal, provincial and local agencies, local industries, and others continue to have a positive impact on restoring water quality and ecosystem health within the Toronto and Region Area of Concern (AOC).
Why was it listed as an Area of Concern?
The Toronto region was designated as an AOC in 1986 because a review of available data indicated that water quality and environmental health were severely degraded. Centuries of agriculture and urban development dramatically reshaped the natural environment of the region. In the Toronto and Region AOC’s Remedial Action Plan (RAP) report, Clean Waters, Clear Choices: Recommendations for Action (1994), eight beneficial uses were identified as impaired and three were identified as requiring further assessment.
What has been accomplished?
Since the RAP began in 1987, agencies, municipalities and non-governmental organizations have worked together to improve the environmental conditions in the Toronto AOC. Implementation of remedial and restoration actions began in 1994 and has led to significant and demonstrable improvements in the quality of water and sediment, the amount and condition of terrestrial and aquatic habitats, and the health of aquatic biota and aquatic communities.
As an example:
- phosphorus levels along the waterfront now meet the mesotrophic target set for the RAP
- there has been a substantial reduction in loadings of E. coli bacteria to the waterfront which has resulted in a steady decline in beach closings
- the health of benthic communities has improved
- the creation of hundreds of hectares of terrestrial and aquatic habitat along streams and along the waterfront have improved conditions for both fish and wildlife
- there are fewer restrictions on the amounts of fish that consumers can eat due to declines in polychlorinated biphenyls and mercury in fish
A measure of progress is that 5 of the original 11 beneficial uses identified as “impaired” or “requires further assessment” have now been re-designated as “not impaired”. These beneficial use impairments (BUIs) are:
- bird or animal deformities or reproductive problems (2011)
- fish tumors or other deformities (2011)
- degradation of benthos (2016)
- restrictions on dredging activities (2016)
- degradation of aesthetics (2020)
Assessments are nearing completion for three more BUIs:
- restrictions on fish and wildlife consumption
- eutrophication or undesirable algae
- beach closings
In terms of water quality, the City of Toronto has made significant progress in implementing the Don River and Central Waterfront Combined Sewer Overflow project to capture, store and treat combined sewer discharges, which is a priority action identified in the Toronto and Region RAP. The 25-year, $3 billion project is scheduled for completion by 2038.
Eight of Toronto’s ten beaches are now certified as Blue Flag beaches, up from four in 2005 and six in 2007. This reflects their high standards for water quality, along with other factors such as environmental education, environmental management, safety and services. The remaining non-Blue Flag beaches—Marie Curtis Park East Beach, Sunnyside Beach and Rouge Beach (managed by Parks Canada)—are near the mouths of creeks and rivers and are affected by stormwater and other inputs of pollution into these tributaries. Extensive surveillance and microbial source tracking analyses has been completed to identify the causes of beach postings at Marie Curtis East Park and Sunnyside Beaches.
In addressing the degradation of fish and wildlife habitat and populations, significant progress has been made through Aquatic Habitat Toronto (AHT)—a unique, collaborative organization responsible for implementing the Toronto Waterfront Aquatic Habitat Restoration Strategy (TWAHRS)—in support of the Toronto and Region RAP. AHT is comprised of representatives from Fisheries and Oceans Canada, Ontario Ministry of Natural Resources and Forestry, Toronto and Region Conservation Authority, the City of Toronto, Ports Toronto and Waterfront Toronto. Considerable efforts have been made to protect and restore habitats for fish and wildlife within the Toronto and Region AOC. The development and implementation of TWAHRS has resulted in extensive restoration work being done in Tommy Thompson Park and along the Toronto waterfront. In 2024, more than 30 hectares of wetland and riparian habitat were created under the $1.35 billion Don Mouth Naturalization project to reduce flooding and create a more natural river mouth.
What is left to do?
Implementation of the City of Toronto’s Wet Weather Flow Management Plan continues to be a priority for the AOC and will significantly improve water quality on the Toronto waterfront.
The restoration of coastal wetland habitat for fish and wildlife is a priority for Toronto, due to the historic filling of 428 hectares of Ashbridges Bay Marsh on the Don River mouth to create Toronto’s port facilities. As such, the continued implementation of the TWAHRS is key to ensure that waterfront projects incorporate improvements to aquatic habitats and fishery resources to create a more liveable and sustainable waterfront.
Outlook
Under the Canada-Ontario Agreement on Great Lakes Water Quality and Ecosystem Health, Canada and Ontario will continue to make significant progress towards remedial action implementation, environmental recovery and restoration of beneficial uses in the Toronto and Region AOC. It is anticipated that actions will be completed after 2026.
Partners
Efforts in Toronto and Region AOC are undertaken in a partnership between the Government of Canada, other levels of government and non-government groups, including members of the public. Undertaking environmental restoration requires a large amount of scientific and technical expertise, local knowledge and hard work. One agency or group cannot engage in such a large task on its own without the help of others.
Listed below are participants that have contributed to efforts in Toronto and Region AOC: