The Fukashiro Dam is a gravity dam in the Sagami River system, located 11 km (7 mi) north of Ōtsuki in Yamanashi Prefecture, Japan. The purpose of the dam is flood control and water supply. Plans for the dam were drawn up in 1978 and construction on the diversion tunnels began in 1996. The dam reached its height in 2001 and in 2003, the reservoir began to fill.By 2004, the entire dam was complete. It is 87 m (285 ft) tall and 164 m (538 ft) long at the crest.The dam's main spillway consists of five free overflow openings with a 790 m3/s (27,899 cu ft/s) discharge capacity.