A draft report from U.S. regulators recommends renegotiating a cross-border treaty that governs the Columbia River.

The Columbia River treaty governs everything from power prices and water supplies.

U.S. regulators say the treaty with Canada should be reworked to make the system more flexible amid climate change, and to aid endangered species.

The Columbia is North America's fourth-largest river and is 2,000 kilometres long.

Chronic flooding problems prompted negotiations between the two countries to ensure better management of the river's dams and reservoirs.

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The Duncan Dam, in the Purcell Mountains, is one of four dams included in the Columbia River Treaty. (Government of B.C.)

The agreement, signed in 1961, led to the flooding of the once agriculturally-rich Columbia Valley. Four dams were built: the Duncan Dam, Mica Dam and Keenleyside Dam in Canada, and the Libby Dam in the U.S.

The treaty was meant to address downstream flooding and to maximize hydropower generation. The U.S. agreed to pay Canada $64 million for flood control and agreed to send electricity generated at downstream U.S. hydropower dams to Canada.

The treaty has no expiration date, but either country may cancel it or suggest changes beginning in 2024 with 10 years notice.