Ohtsu Dam
Location of Ohtsu Dam in Japan
Location	Gunma Prefecture, Japan
Coordinates	36°33′05″N 138°37′38″E / 36.55139°N 138.62722°E / 36.55139; 138.62722
Construction began	1928
Opening date	1931
Dam and spillways
Type of dam	Gravity
Impounds	Agatsuma River
Height	19.6 m (64 ft)
Length	73.9 m (242 ft)
Reservoir
Total capacity	108,000 m3 (3,800,000 cu ft)
Catchment area	451 km2 (174 sq mi)
Surface area	4 hectares

Ohtsu Dam is a gravity dam located in Gunma Prefecture in Japan. The dam is used for power production. The catchment area of the dam is 451 km². The dam impounds about 4 ha of land when full and can store 108 thousand cubic meters of water. The construction of the dam was started on 1928 and completed in 1931.^[1]