| Seidai Dam | |
| Location: | Hokkaido Prefecture, Japan |
| Dam Length: | 485.4m |
| Dam Height: | 29.7m |
| Opening: | 1937 |
| Res Capacity Total: | 3767 thousand cubic meters |
| Res Catchment: | sq. km |
| Res Surface: | 51 hectares |
| Coordinates: | 43.6119°N 142.5242°W |
| Location Map: | Japan |
Seidai Dam is an earthfill dam located in Hokkaido Prefecture in Japan. The dam is used for irrigation. The dam impounds about 51 ha of land when full and can store 3767 thousand cubic meters of water. The construction of the dam was completed in 1937.[1]