 The dam is gravity type concrete dam with a height of 76.0 m. 

During torrential rains in 1965, the capacity of Sasogawa Dan was greatly overwhelmed, and considerable damage occurred to the dam and to downstream settlements.Improvements were made to the dam from 1972 to 1977 increase its capacity to handle torrential rains by construction of a flood discharge tunnel on the right bank of the dam and improvement in communication and observation facilities for emergency situations.Due to these improvements, torrential rains in 2004 did not cause any further damage.