The Columbia River Treaty was an agreement between Canada and the United States of America signed in 1961 and ratified in 1964 to develop the Columbia River with several hydro-electric dams and to prevent spontaneous flooding of the Columbia Basin.
There was initial controversy over the Columbia River Treaty as British Columbia refused to give consensus to ratify it on the grounds that while the province would be committed to proceed with the building of three major dams within its borders on the Columbia River, it would have no assurance of a purchaser for downstream power. The final ratification came in 1964 when the United States agreed to pay to Canada the sum of $274.8 million dollars and an additional total amount of $69.6 million to be paid in installments once each dam was completed (the Duncan dam , Keenleyside dam , and Mica dam respectively). These dams (with the exception of the Mica dam) were initially built for the sole purpose of regulating water flow. The Mica dam has a powerhouse and construction of a powerhouse at the Keenleyside dam is presently underway at Castlegar, British Columbia.
The Columbia River Treaty, while intended to benefit Canadians, actually lost them far more money than what the Americans had paid as compensation. In the treaty, Canada had also agreed that the United States could build the Libby dam on the Kootenay River which, when finished, subsequently flooded several square kilometres of fertile farm land in the Kootenay Valley which was potentially worth well over the $344.4 million the Americans had promised to deliver. The flooding of the Kootenay Valley also destroyed many ancient Native American archælogical sites and artifacts which can now never be uncovered.