Great Lakes water quality agreement

Official title: Great Lakes Water Quality Agreement

Subject category:
Type of agreement / instrument:
Canada - United States
Legally-binding treaty
  • Signed: April 15, 1972.
  • Revised in: 1978.
  • Amended by Protocol in: 1987.
  • Amended by Protocol in: 2012.
Lead & partner departments:
Environment and Climate Change Canada
Fisheries and Oceans Canada and Transport Canada
For further information:
Web links:
Compendium edition:
January 2020
Reference #:

Plain language summary

The Great Lakes are shared by Canada and the United States and are vital to the well-being of millions of people. Among other things, they:

  • contain almost 20% of world's surface freshwater
  • sustain 4,000 species of plants and animals
  • Are the basis for billions of dollars in economic activity
  • Provide drinking water for tens of millions of Canadians and Americans

The Great Lakes Water Quality Agreement (GLWQA) between Canada and the United States was first signed in 1972. It identifies shared priorities and actions needed to restore and protect the Great Lakes.

The Agreement was modernized in 2012 to reflect new knowledge and tackle all issues affecting Great Lakes water quality and ecosystem health.


The 2012 Canada-United States GLWQA commits the governments of Canada and the United States to restore and protect the Great Lakes to achieve a series of objectives including: being a source of safe, high-quality drinking water; allowing for swimming and other recreational use, unrestricted by environmental quality concerns; allowing for human consumption of fish and wildlife unrestricted by concerns due to harmful pollutants.

Key elements

The GLWQA includes commitments to both short-term and long-term action; enhances transparency and accountability; reflects current knowledge and understanding; and focuses on anticipating and preventing new problems.

The GLWQA comprehensively addresses priority challenges to the water quality and ecosystem health of the Great Lakes organized by 10 issue annexes: Areas of Concern; Lakewide Management; Chemicals of Mutual Concern; Nutrients; Discharges from Vessels; Aquatic Invasive Species; Habitat and Species; Groundwater; Climate Change Impacts; and Science.

Through the Agreement, Canada and the United States (the Parties) commit to work toward attaining a series of general and specific objectives related to the quality of the waters of Great Lakes.

Expected results

Through the Agreement, Canada and the United States, in cooperation and consultation with other levels of government, indigenous peoples, non-governmental entities and the public, work to restore and protect Great Lakes water quality and ecosystem health.

Canada’s involvement

As a Party to the Agreement, Canada is responsible for implementing programs and reporting on progress in restoring and protecting the Great Lakes.

Environment and Climate Change Canada leads implementation of the Agreement, working in collaboration with a number of departments, agencies and organizations on both sides of the boarder representing governments, Indigenous peoples, watershed management agencies, and other local public agencies. Canada collaborates and cooperates with the Government of Ontario through the 2014 Canada-Ontario Agreement on Great Lakes Water Quality and Ecosystem Health, which helps coordinate the activities of eight federal departments and three provincial ministries in order to support implementation of the GLWQA.

Results / progress


The Great Lakes Executive Committee (GLEC) serves as a forum to advise and assist the parties in coordinating, implementing, reviewing and reporting on programs, practices and measures that support the implementation of the GLWQA. The GLEC, co-chaired by Environment and Climate Change Canada and the U.S. Environmental Protection Agency, includes senior-level representatives from Federal Governments, State and Provincial Governments, Tribal Governments, First Nations, Métis, Municipal Governments, watershed management agencies, and other local public agencies.  A formal committee structure has also been established to engage GLEC member organizations in working binationally to develop and implement actions to achieve commitments for each of the ten issue areas identified in the GLWQA.


Every three years under the GLWQA, the Parties are required to report publically on their progress through the Progress Report of the Parties, as well as report on the state of the Great Lakes using a suite of science-based, comprehensive ecosystem indicators. In addition, other issue specific reporting requirements are set out in the GLWQA Annexes. The International Joint Commission has been charged with reviewing and evaluating the Parties’ progress. The first Progress Report of the Parties, issued in 2016, can be found online. The second Progress Report of the Parties Parties, also available on, was released in advance of the 2019 Great Lakes public forum.


The Parties continue to make significant progress across the range of issues addressed by the GLWQA. The 2019 Progress Report of the Parties outlines the accomplishments over 2016 to 2019 in implementation of the GLWQA.

In the International Joint Commission First Triennial Assessment of Progress report, the Commission commends the Parties for considerable progress related to accelerating the clean-up of contaminated Areas of Concern; setting new phosphorus loading targets entering Lake Erie in order to reduce harmful algal blooms; and galvanizing new energies and binational cooperation to implement the Agreement and address a wide range of Great Lakes issues. The Commission also provided recommendations for several key areas that they noted required increased attention.

The Commission’s Second Triennial Assessment of Progress Report will be released in 2020. Recommendations from the Commission’s Triennial Assessment of Progress Reports are taken into consideration as governments enhance GLWQA implementation efforts.

The 2019 Progress Report of the Parties (to be made available on will outline the accomplishments and progress pursuant to the GLWQA over 2016 to 2019.

As GLWQA implementation efforts continue, further information will be made available on

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