Sannōkai Dam

The Sannōkai Dam (山王海ダム, Sannōkai damu) is a dam on the Toyosawa River, a tributary of the Kitakami River system, located in the town of Shiwa, Iwate Prefecture in the Tōhoku region of the island of Honshū, Japan. It completed in 1952.

Sannōkai Dam
Location of Sannōkai Dam in Japan
Official name	山王海ダム
Location	Shiwa, Iwate, Japan
Coordinates	39°32′51″N 141°03′53″E
Construction began	1973
Opening date	2001
Operator(s)	Iwate Prefecture
Dam and spillways
Impounds	Takina River
Height	61.5 meters
Length	235.0 meters
Reservoir
Creates	Heian Lake
Total capacity	37,600,000 m3
Catchment area	37.7 km2
Surface area	250.0 hectares

History

The need for storage reservoirs in the Kitakami River valley for irrigation purposes was recognized by the Meiji government at the start of the 20th century, due to repeated crop failures and conflicts between various communities over water rights, dating even from the early Edo period. The river also suffered from severe environmental problems with acidic runoff from upstream mining operations. Plans for a series of dams was initiated in 1941 by the Ministry of Agriculture and Forestry, but all work was halted during World War II. The plan was revived after the war, and the Sannōkai Dam was the first to be constructed.

Design

The Sannōkai Dam was started in 1947 and was completed in 1952 as a 37.4-foot high earthen embankment dam. However, due to aging and concerns over safety, it was completely rebuilt starting in 1977 as a rock-fill dam, with its height raised to 61.5 meters. The new dam was completed in 2001.

References

• Japan Commission on Large Dams. Dams in Japan: Past, Present and Future. CRC Press (2009). ISBN 978-0-415-49432-8

External links

Media related to Sannokai Dam at Wikimedia Commons

• photo page with data ((in Japanese)
• Official home page (in Japanese)