As a nation of islands and narrow, steep valleys, dams play a vital role in Japanese society as they are constructed primarily to control floods, supply water and generate hydroelectric power. The tallest dam in Japan is the 186 m (610 ft) high Kurobe Dam. The largest dam by structural volume in the country is the Tokuyama Dam (pictured) with 13,700,000 m3 (17,900,000 cu yd) of rock-fill. Tokuyama also creates Japan's largest reservoir with a water volume of 660,000,000 m3 (540,000 acre⋅ft).
The dams are arranged by prefecture in the list below.