Our vision for Toronto and Region is a healthy ecosystem that supports the well-being of local communities.


map of Great Lakes Areas of Concern

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Toronto and Region is one of 43 locations around the Great Lakes where local environmental degradation may be causing harm to the wider Great Lakes system. These locations, referred to as Areas of Concern (AOCs), are located in Canada (12 sites), the United States (26 sites), and in some cases are shared between the two countries (5 sites).


Areas of Concern were formally recognized by the governments of Canada and the United States in the 1987 amendments to the Great Lakes Water Quality Agreement.This Agreement committed the governments of each country to clean up Areas of Concern within their respective jurisdictions.


The status of an Area of Concern is determined by assessing the state of local environmental conditions against fourteen different Beneficial Use Impairments (BUIs), as identified in the Great Lakes Water Quality Agreement. Each Beneficial Use Impairment describes a human or ecological use of the ecosystem that has been lost or impaired as the result of environmental degradation; an AOC is therefore considered impaired when local conditions meet the descriptions of one or more BUIs.  The clean-up, or remediation, of an Area of Concern occurs through a mandated process called a Remedial Action Plan, or RAP. An individualized RAP is required for each Area of Concern.


“]In Ontario, the responsibilities for RAP progress and Area of Concern remediation are shared by the federal and provincial governments through the Canada-Ontario Agreement Respecting the Great Lakes Basin Ecosystem, or COA.  The administration and implementation of a RAP, however, includes a variety of departments at all levels of government, non-governmental organizations, academia, business and industry, and the public.  A local RAP team tracks environmental conditions, activities, and outcomes relevant to the RAP.


The Toronto and Region Remedial Action Plan (RAP) is managed by representatives from Environment and Climate Change CanadaOntario Ministry of the Environment, Conservation, and ParksOntario Ministry of Natural Resources and Forestry, City of Toronto, and Toronto and Region Conservation Authority (TRCA).


The Toronto and Region Area of Concern extends along the north shore of Lake Ontario from Etobicoke Creek in the west to the Rouge River in the east. The 2000 square kilometer area includes 6 watersheds and 42 km of waterfront, spanning eleven municipal jurisdictions with over 3 million residents.



Toronto and Region is currently in Stage 3 (implementation) of the RAP process.  Three major interim progress reports, Clean Waters, Healthy Habitats: 2001 RAP Progress Report (2001), Moving Forward: 2007 RAP Progress Report (2009), Within Reach: 2015 RAP Progress Report (2016) and have been issued that detail environmental monitoring results, achievements in remediation initiatives, as well as how conditions in Toronto and Region’s compare against the Beneficial Use Impairment criteria. A full listing of available Toronto and Region RAP updates is available here.


Although the challenges are many, the Toronto and Region RAP team believes that completing all restoration actions by 2020 is within reach.


Eutrophication or undesirable algae Beach closings Restrictions on fish or wildlife consumption Degradation of
Restrictions on
dredging activities
Loss of fish and
wildlife habitat
Degradation of fish and wildlife populations Degradation of aesthetics
Degradation of phytoplankton
and zooplankton communities
Bird or animal deformities or reproductive problems Fish tumours or other deformities Restrictions-drinking water consumption-taste/odor problems
Added costs to agriculture or industry Tainting of fish and wildlife flavor



Not impaired Impaired Further study/assessment required