Red Bluff Diversion Dam

The dam is a concrete gated weir design, long, with a structural height of . Eleven fixed wheel gates, each wide and high, control the outflow of water to the Sacramento River. The concrete piers between the gates are in width. Lake Red Bluff, formed by the dam when the gates are lowered, had a maximum depth of , a normal storage of , and a maximum storage of . A diversion headworks and settling basin on the south bank of the Sacramento River originally provided a gravity flow of water to two aqueducts, the Tehama-Colusa Canal and Corning Canal. The headworks consist of six radial gates with a capacity of . The Tehama Colusa Canal, larger of the two canals, is long, with a capacity of . The Corning Canal is long and can carry . The total crop value is $250 million, with total benefits of $1 billion per year to the regional economy. ==Construction history==

Although the Central Valley Project was initially authorized in 1935, the Sacramento Canals Division was not authorized until September 29, 1950 by President Harry Truman. The contract for construction of Red Bluff Diversion Dam was awarded in 1962 to Vinnell Corporation, for a total of $3,465,155. Work on the dam began in 1962 and was completed on August 9, 1964, more than 4 months ahead of schedule. The Corning Canal had been completed by 1959, but the much larger Tehama Colusa Canal was not completed until 1980. ==Environmental impact==

While the dam is relatively small, it has historically blocked passage of salmon, steelhead and sturgeon runs on the Sacramento River with resulting detrimental impact on these fish populations. This occurred both due to improper construction of the fish ladders on the dam, and turbulence caused by water diversion which disorient migrating fish. A fish screen was installed between 1969 and 1971 to prevent fish from entering the canal headworks, By 2008, the dam gates were open in all months except for the primary irrigation season of mid-May to mid-September, but the migrating fish count remained low. In 2013, the Bureau of Reclamation awarded E.C. Smith Inc. a contract of $3.28 million to decommission the dam. While the dam is not planned to be removed, its gates are permanently locked in the open position. The decommissioning has been controversial, as it resulted in the loss of Lake Red Bluff, the reservoir originally formed behind the dam and a popular recreation spot in the area. The total cost of restoring fish populations above Red Bluff Dam has reached about $180 million. ==See also==