Senzu 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 2002, it was estimated that over 97.7% of the usable capacity of Senzu Dam was filled with mud, and must now be constantly dredged to permit flow of water for power generation.

The area is popular with mountain climbers heading towards the high peaks of the Minami Alps National Park.