The Columbia River Treaty is a trans-boundary water management agreement between the United States and Canada signed in 1961 and ratified in 1964.
The Columbia River is approximately 2000 kilometres long and is the largest North American river emptying into the Pacific Ocean.
It begins in British Columbia at Columbia Lake and winds through British Columbia and Washington before emptying into the Pacific Ocean, near Portland, Oregon. The Kootenay River is the major uppermost tributary of the Columbia River and joins the Columbia River at Castlegar, British Columbia.
The Treaty grew out of two major challenges: devastating flooding to areas close to Columbia River in both Canada and the United States and the need for more electricity to support a growing economy and population in the Pacific Northwest.
The purpose of the Columbia River Treaty is to optimize flood management and power generation. This requires coordinated operations of reservoirs and water flows for the Columbia River and Kootenay River on both sides of the border.
Either Canada or the U.S. can unilaterally terminate most of the provisions of the Columbia River Treaty any time after September 16, 2024, providing at least ten years’ notice is given. The latest date to provide termination notice for September 2024 was September 2014.
The Canada-British Columbia Agreement (1963) transferred most Columbia River Treaty benefits, rights and obligations to British Columbia, requiring Canada to obtain B.C.’s agreement before amending or terminating the Treaty.
Under the Columbia River Treaty, Canada (British Columbia) agreed to build three dams [Duncan (1967), Arrow/Hugh Keenleyside (1968) and Mica (1973)], and in return received benefits based on the additional flood control and power generation potential. British Columbia received an upfront one-time payment of $64 million for 60 years of assured flood control.
Regardless of termination, Assured Annual Flood Control expires automatically in 2024 and converts on 16 September 2024 to a Called Upon operation of Canadian storage space as may be needed by the United States for flood risk management once the United States has made effective use of all its reservoirs to reduce flood risk. “Called Upon” flood control continues for as long as the dams that provide it are in place, even if the Columbia River Treaty is terminated.
Canada’s half share of the additional power that could be generated in the United States as a result of the dams, the downstream power benefits, is called the Canadian Entitlement. Under the 1963 Canada-British Columbia Agreement, these benefits are owned by the Province of British Columbia.
British Columbia sold the first 30 years of the Canadian Entitlement to a consortium of utilities in the United States for $254 million and used the money to finance the construction of the three Columbia River Treaty dams.
The Canadian Entitlement continues as long as the Columbia River Treaty is in place. If the Columbia River Treaty is terminated, the Canadian Entitlement ends.
The Columbia River Treaty also provided for the construction of the Libby dam (1973) in Montana and the resulting reservoir, Lake Koocanusa, stretches back 68 kilometres into British Columbia.
The Libby dam regulates water flow on the Kootenay River, the major uppermost tributary of the Columbia River. The obligation to regulate water flow on the Kootenay River continues indefinitely, even if the Columbia River Treaty is terminated.