Canada-US Columbia River treaty

Official title: Treaty between Canada and the United States of America Relating to Cooperative Development of the Water Resources of the Columbia River Basin (Columbia River Treaty)

Subject category:
Type of agreement / instrument:
Canada - United States (U.S.)
Legally-binding treaty
  • Signed: January 17, 1961
  • Ratified: September 16, 1964
  • Came into force: September 16, 1964
  • Termination: No fixed termination date. Earliest termination is 2024. Termination requires 10 years notice
  • Treaty renewal is currently underway through ongoing negotiations
Lead & partner departments:
Natural Resources Canada and Global Affairs Canada
Department of Fisheries and Oceans, Crown-Indigenous Relations and Northern Affairs Canada, Environment and Climate Change Canada
For further information:
Web links:
Compendium edition:
July 2022
Reference #:

Plain language summary

The Columbia River Treaty (Treaty) is a 1964 agreement between the governments of Canada and the U.S. that required large hydroelectric dams to be built (3 in Canada and 1 in the U.S.) for optimal year production of electricity and reduced risk of devastating floods. The Canadian dams are in British Columbia and operated by BC Hydro. The U.S. pays Canada (i.e., Canadian Entitlement) for the additional power generation that results from operation of the Canadian dams ($180–300 million dollars per year). The Treaty is considered a model of international cooperation on transboundary water management and hydropower development. Because of a 1963 agreement between Canada and the province of B.C., B.C. carries most of the Treaty responsibilities (and benefits) for Canada, while U.S. operations are run by federal agencies.   


In 1964, Canada and the U.S. entered into the Treaty. Under the terms of the Treaty, three dams were constructed on the Canadian side of the basin for the purpose of providing flood control and maximizing hydroelectric power generation.

Key elements

Based on a referral by both the Canadian and U.S. governments, joint Canada-U.S. Engineering studies were initiated in 1944 through formation of the International Columbia River Engineering Board under the International Joint Commission (IJC) leading to recommendations for hydro-power development.

In accordance with the terms of the Treaty, Canada constructed three reservoirs on the Canadian side of the basin from 1967 to 1973 (Duncan Dam, Hugh Keenleyside Dam and Mica Dam, in order of construction) and receives, in return, one-half of the additional electricity generation and payment for increased flood control benefits enabled on the U.S. side as a result of this additional storage. In 1975, the U.S. constructed one dam under the Treaty resulting in a transboundary reservoir (Libby Dam/Lake Koocanusa). The Treaty may not be terminated sooner than 60 years from its ratification (i.e., 2024), and even if terminated, parts of the Treaty pertaining to flood control remain in effect (although mode of flood control would change from an assured to called-upon regime). Ten years notice is required for each Party to indicate its desire for termination.

Canada operates 15.5 Million Acre-Feet (19,119Mm3) of reservoir storage for optimum power generation and flood control in Canada and the U.S.

At the time of Treaty ratification, the first 30 years of Canadian Entitlement was sold to a consortium of U.S. utilities for US$254.4 M.

The U.S. also provided an up-front purchase of 8.45 Million Acre-feet (10,422 Mm3) of primary flood control capacity from the Canadian reservoirs through to 2024 for US$64.4 M.

Pre-sale of power and flood benefits helped to pay for construction of the three Canadian Treaty dams by the government of British Columbia.

Resulting from Treaty obligations, 110,000 hectares (270,000 acres) of Canadian ecosystems were inundated; local community residents, First Nations and infrastructure were displaced, with impacts to cultural heritage, agricultural and forestry activities.

The Treaty pre-dates current Canada and U.S. domestic environmental protection legislation and focuses on power generation and flood control as its primary purposes. Domestic environmental issues such as protection of species at risk are currently addressed outside of the Treaty. There is some operational flexibility in the Treaty to address a range of water management requirements (e.g., fisheries issues) through supplementary operating plans and infrastructure modifications (etc.).

Expected results

Coordinated operations of Canadian and U.S. hydro-power and reservoir storage facilities in the Columbia River Basin.

Greatly reduced risk of devastating floods as per the Columbia River flood which destroyed the city of Vanport, OR., in 1948.

Predictable and dependable hydro-power generation for Canada and the U.S. to support regional economic development.

Canada’s involvement

All commitments and financial returns pertaining to the Treaty were assigned by Canada to British Columbia through the 1963 British Columbia-Canada agreement (and 1964 supplementary agreement). British Columbia has designated BC Hydro as the “Canadian Entity” to deliver on the river management terms of the treaty.

Natural Resources Canada (NRCan) participates on the CRT Permanent Engineering Board to help oversee delivery of Treaty commitments. Canada does not have an Act of Parliament pertaining to this Treaty but implemented the International River Improvements Act in 1955 to provide federal approval of such projects on Canada-U.S. transboundary rivers. The Canadian dams are licensed through Environment and Climate Change Canada under this Act, with 50-year license terms recently renewed in 2015, although conditional with continuation of the Treaty.

Environment and Climate Change Canada provides atmospheric and hydrometric monitoring services to support Treaty operations as outlined in various agreements with BC Hydro.

Results / progress


NRCan actively participates in secretariat support and membership on the CRT Permanent Engineering Board.

The potential to terminate the Treaty by 2024 resulted in a period of Columbia River Treaty review including evaluations of domestic benefits associated with the Treaty by groups and agencies on both sides of the border. These Treaty review activities were initiated by key agencies in advance of the initial date for announcement of intent to terminate (2014). The Canadian entity, through the province of British Columbia, issued its position for continuation of the Treaty on March 13, 2014, while the U.S. entity provided a regional recommendation to the Department of State on December 13, 2013, which resulted in a national interest review process at the federal level and the development of a U.S. negotiating team.

On May 29, 2018, Global Affairs Canada initiated a formal negotiation process with the U.S. towards renewal of the Columbia River Treaty. Treaty negotiations are ongoing.


Annual Reports are available on the website of the Permanent Engineering Board.

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