| Matanogawa Dam | |
| Location Map: | Japan |
| Coordinates: | 35.2456°N 133.4917°W |
| Country: | Japan |
| Location: | Kōfu |
| Status: | O |
| Construction Began: | 1978 |
| Opening: | 1984 |
| Owner: | Chugoku Electric Power Company |
| Dam Type: | Concrete gravity |
| Dam Height: | 69.3m (227.4feet) |
| Dam Length: | 185m (607feet) |
| Dam Volume: | 165000m2 |
| Dam Crosses: | Hino River tributary |
| Res Capacity Total: | 7940000m2 |
| Res Capacity Active: | 6700000m2 |
| Res Catchment: | 48.9km2 |
| Res Surface: | 41ha |
| Plant Commission: | 1992-1996 |
| Plant Turbines: | 4 x 300MW Francis pump-turbines[1] |
| Plant Capacity: | 1200MW |
The Matanogawa Dam (俣野川ダム) is a concrete gravity dam on a tributary of the Hino River located 2.30NaN0 south of Kōfu in Tottori Prefecture, Japan. Construction on the dam began in 1978 and it was complete in 1984. The primary purpose of the dam is hydroelectric generation and it creates the lower reservoir for the Matanogawa Pumped Storage Power Station (俣野川発電所). It is tall and creates a reservoir with a 7940000m2 storage capacity. The power station is located on the southern bank of the reservoir and contains four Francis pump-turbine-generators. The upper reservoir for the pumped-storage scheme is created by the Doyo Dam located to the southeast in Okayama Prefecture. To generate power, water from the Doyo Dam is sent to the power station, used to generate electricity and then discharged into the Matanogawa Reservoir. This occurs when energy demand is high and when it is low, water is pumped back up to the Doyo Dam as stored energy. The same pump-generators that pump the water to Doyo reverse and generate electricity when it is sent back down. The first generator was operational in 1992 and the last in 1996.[2]