Even though the four dams [Duncan, Mica, Arrow (Hugh Keenleyside), Libby] improved flood control and power production, the resulting reservoirs in Canada flooded 60,000 hectares (231 square miles) of valley land.

Flooding impacted traditional First Nations’ sites, agricultural and forestry areas, displaced a dozen communities, including approximately 2,300 people, and impacted fish and wildlife habitat.

The rise and fall of reservoir levels continue to affect the surrounding ecosystems, cultural and recreation interests.

In recognition of the long-term impacts in the region as a result of the Columbia River Treaty and the Columbia River Treaty dams, Columbia Basin Trust (a Crown corporation) was created in 1995 to promote social, economic and environmental well-being in the Columbia River Basin.