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
Mantasoa Dam Mantasoa Dam Mantasoa Dam is a buttress dam on the Varahina-North River, a tributary of the Ikopa River, near Mantasoa in the Analamanga Region of Madagascar. The dam was constructed by the French Business Company between 1937 and 1938. It creates Lake Mantasoa which has a surface area of . The dam itself is made of of concrete and has a reinforced buttress design. Water released from the dam supplies a regulated flow to hydroelectric power station at the Antelomita Dams downstream. A saddle dam on the north side of the Mantosoa reservoir regulates water flow into the Mandraka River