The potential of the Tenryū 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.

Preliminary design work began in 1962, with construction beginning in 1969 after some opposition from the 100 households who needed to be relocated, and over increasing controversy regarding the issues of dams on the Tenryū and Ōi rivers rapidly filling with sand and silt from the mountains upstream, with the resultant reduction of the amount of sand and silt reaching the river mouth creating problems with coastal erosion.

It impounds a reservoir called Lake Midori (はみどり湖, midoriko) with a surface area of 156.0 hectares (385 acres).

[1] The Shintone Dam Reservoir is a popular attraction as the surrounding area is part of the Tenryū-Okumikawa Quasi-National Park.