The project was constructed by PacifiCorp between 1947 and 1956.[1] The original federal license to operate the project was issued in 1947 for a period of 50 years, expiring in 1997.[2] A settlement agreement to renew the license was approved in 2001 after prolonged negotiations between PacifiCorp and numerous state and federal agencies.[3]
The project consists of eight dams, three reservoirs, and miles of flumes, canals, penstocks and tunnels.[1][4][5]
Conservationists have criticized the hydroelectric facilities for their impact on the ecology of the North Umpqua River watershed.[6][7] Particular focus has been placed on the Soda Springs Dam, which restricts salmon and steelhead from swimming to spawning grounds upstream. A fish ladder allowing them upstream passage was completed in 2012 at a cost of $60 million.[8][9][10]