In 1964, Canada and the United States (U.S.) ratified the Columbia River Treaty (Treaty), a transboundary water management agreement.

The impetus for the Treaty was the disastrous flood of 1948 which devastated the City of Vanport in Oregon and cost many lives, along with growing power demand in the Pacific Northwest. In exchange for providing flood control and for an equal share of the incremental U.S. downstream power benefits, Canada agreed to build three dams – Duncan, Hugh L. Keenleyside and Mica – in British Columbia and allowed the U.S. to build a fourth dam, the Libby Dam, that flooded into Canada.

The Canadian facilities vastly reduced flood risk in B.C. and the U.S. The Treaty also enabled the construction of hydroelectric projects in B.C. that provide approximately half of the potential generation in the province, as well as providing for the production of significantly more electricity at U.S. hydropower facilities.

The Canada-British Columbia Agreement (1963) allocated most Treaty rights, benefits and obligations to the Province. Although this agreement retains Canada’s constitutional jurisdiction for international treaties, it requires Canada to obtain the concurrence of the Province before terminating or amending the Treaty

The U.S. prepaid Canada $64 million for 60 years to provide assured flood control operations which resulted in reduced flood damage and increased safety for U.S. citizens. The U.S. also committed in the Treaty to paying Canada half of the incremental power potential that could be produced because of the new flow regimes made possible by the Treaty coordination.

The Treaty dams and reservoirs inundated 110,000 hectares (270,000 acres) of Canadian ecosystems, displaced more than two thousand residents as well as First Nations, communities and infrastructure, and impacted farms, tourism and forestry activities. First Nations and public consultation and mitigation at the time could be considered inadequate to non-existent by today’s standards, and feelings of hurt remain to this day.

The Treaty has no end date but either country can unilaterally terminate the Treaty from September 2024 onwards provided that at least 10 years notice is given.

This ability to terminate the Treaty, and the changing flood control provisions that will occur post-2024 whether the Treaty is terminated or not, have prompted both countries to undertake a review of the Treaty to determine its future.