Sasamagawa Dam

The potential of the Ōi River valley for hydroelectric power development was realized by the Meiji government at the start of the 20th century.

Its mountainous upper reaches and tributaries were areas of steep valleys and abundant rainfall, and were sparsely populated.

In 1906, a joint venture company, the Anglo-Japanese Hydroelectric Company (日英水力電気, Nichiei Suiroku Denki) was established, and began studies and design work on plans to exploit the potential of the Ōi River and Fuji River in Shizuoka Prefecture.

By the mid-1950s, numerous dams had been constructed on the main flow of the Ōi River, and developers began to turn their attention to its various tributary streams.

The dam serves a secondary purpose in providing water for irrigation to farms in the surrounding area.