- Boundary Waters Treaty established early principles and procedures for studying and resolving issues related to U.S./Canada joint use of the Columbia River. Treaty affirmed Canada’s power to divert or regulate cross-border flows.
- Development of the river for hydropower begins.
- Rock Island Dam powerhouse completed in 1933. It was the Columbia River’s first.
- Construction begins on Grand Coulee Dam, 1933
- Bonneville Dam and locks completed, 1937
- U.S. and Canadian governments probe feasibility of creating a joint Columbia River flood control and hydropower system.
- Grand Coulee Dam begins generating in 1942.
- Columbia River’s Memorial Day floodwaters inundated communities in British Columbia and NCW, including Omak and Wenatchee, and destroyed Oregon’s second-largest city, Vanport, where 50 people died.
- More talks about the need for flood controls on the Columbia, including cooperative water storage.
- McNary Dam completed, 1954
- The Dalles Dam completed, 1957
- Chief Joseph Dam completed, 1958
- The U.S. Senate ratifies the Columbia River Treaty, a framework for river’s joint U.S.-Canada operation for flood control and hydropower generation.
- Rocky Reach Dam begins operation.
- Priest Rapids Dam produces first commercial electricity, followed by Wanapum Dam.
- Canada ratifies the Columbia River Treaty. The treaty takes effect.
1967 - 1973
- Treaty-sanctioned dams Duncan, Arrow (renamed Keenleyside) and Mica are completed in Canada. Libby Dam is completed in Montana on the Kootenai River, a tributary of the Columbia. These dams, together, create 20.5 million acre feet of water storage, more than doubling existing Columbia Basin storage.
- Wells Dam produces first power
- John Day Dam completed
- Revelstoke Dam powerhouse completed
- Pro-fish-survival projects proliferate.
- The government agencies charged with operating the treaty, BC Hydro in Canada and the Bonneville Power Administration and Army Corps of Engineers in the U.S., begin analysis of future river operations if the treaty were to continue, be modified or terminated. These are known as the “U.S. Entity” and the “Canadian Entity.”
- U.S. Entity and NCW’s PUDs expect to have results of detailed analysis of how changes to the treaty would affect Columbia River flows and reservoirs.
- U.S. Entity will present its recommendation to the U.S. State Department on whether to continue, amend or terminate the treaty.
- September - The latest that either entity can call for treaty termination when flood-control storage provision ends in 2024.
- Changes on the river would begin.
Source: U.S. Army Corps of Engineers; Bonneville Power Administration; Chelan, Douglas, Grant County PUDs; BC Hydro.