Owyhee Dam A project of the Bureau of Reclamation, they hired General Construction Company from Seattle to build the dam. Former Oregonian and then United States President Herbert Hoover dedicated what was the highest dam of its type in the world on July 17, 1932. Secretary of the Interior Ray Lyman Wilbur delivered Hoover's message at the dam. Owyhee's construction served as a prototype for the larger Hoover Dam on the Colorado River, including the use of refrigeration to cool the concrete. The dam cost $6,000,000, with the total reclamation project costing $18,000,000. Owyhee was designed by Frank A. Banks, who also
Tsukabaru Dam area drained at the dam site is and is highly forested to the extent of 95%, whereas the agricultural area is only 1%. The river catchment lies in a temperate climatic zone. There is cascade of six dams built on the river with two dams in the upstream basin of the Tsukabaru Dam and three dams (Yamasubaru Dam, Saigo Dam, and Ouchibaro Dam) downstream of it. The uppermost dam is the Kamishiba Dam, the first arch dam in Japan which is the largest on the river followed by the Iwayado Dam. Tsukabaru Dam, a concrete masonry gravity dam is in