The Okutataragi Pumped Storage Power Plant is a large pumped-storage hydroelectric power station in Asago, in the Hyōgo Prefecture of Japan. With a total installed capacity of a 1,932 MW, it is one of the largest pumped-storage power stations in the world, and the largest in Japan. The facility is currently run by the Kansai Electric Power Company.

Like most pumped-storage facilities, the power station utilizes two reservoirs, releasing and pumping as the demand rises and falls. Construction on the facility began in 1970 and was completed in 1974.

Kurokawa Reservoir

The Kurokawa Reservoir, the upper reservoir, has a capacity of 33,387,000 m3 (1.1791×109 cu ft), a catchment area of 1,090,000 m2 (11,700,000 sq ft), and a reservoir surface area of 5.2 km2 (2.0 sq mi), and is held back by the Kurokawa Dam.

The embankment dam, located on the Ichi River, measures 98 m (322 ft) tall, 325 m (1,066 ft) wide, and is built with 3,650,000 m3 (129,000,000 cu ft) of material.

Tataragi Reservoir

The Tataragi Reservoir, the lower reservoir, has a capacity of 19,440,000 m3 (687,000,000 cu ft), a catchment area of 1,050,000 m2 (11,300,000 sq ft), and a reservoir surface area of 13.4 km2 (5.2 sq mi), and is held back by the Tataragi Dam.

The dam measures 64.5 m (212 ft) tall, 278 m (912 ft) wide, and is build with 1,462,000 m3 (51,600,000 cu ft) of material.

Okutataragi Pumped Storage Power Station
Country Japan
Locale Asago, Hyōgo
Status Operational
Construction began 1970
Commission date 1974
Operator(s) KEPCO

Reservoir information
Upper reservoir Kurokawa Reservoir
Reservoir capacity 33,387,000 m3
Catchment area 1,090,000 m2
Surface area 5.2 km2
Lower reservoir Tataragi Reservoir
Reservoir capacity 19,440,000 m3
Catchment area 1,050,000 m2
Surface area 13.4 km2

Power generation information
Installed capacity 1,932 MW