Okutadami Dam

Okutadami Dam
Location of Okutadami Dam in Japan
CountryJapan
LocationUonuma
Coordinates37°09′12″N 139°15′00″E / 37.15333°N 139.25000°E / 37.15333; 139.25000
Construction began1953
Opening date1961
Owner(s)Electric Power Development Company
Dam and spillways
Type of damGravity
ImpoundsTadami River
Height157 m (515 ft)
Length475 m (1,558 ft)
Dam volume1,636,000 m3 (2,139,807 cu yd)
Reservoir
CreatesLake Okutadami
Total capacity601,000,000 m3 (487,239 acre⋅ft)
Active capacity458,000,000 m3 (371,307 acre⋅ft)
Catchment area595 km2 (230 sq mi)
Surface area1,150 ha (2,842 acres)
Normal elevation750 m (2,461 ft)
Power Station
Commission date1960, 2003
Hydraulic head120 MW units: 170 m (558 ft)
200 MW unit: 164.2 m (539 ft)
Turbines3 x 120 MW, 1 x 200 MW Francis-type
Installed capacity560 MW

The Okutadami Dam (奥只見ダム) is a concrete gravity dam on the Tadami River, 26 km (16 mi) east of Uonuma on the border of Niigata and Fukushima Prefectures, Japan. The primary purpose of the dam is hydroelectric power generation and it supports a 560 MW power station which is the largest conventional hydroelectric power station in Japan. The dam also forms the second largest reservoir in Japan, next to that of the Tokuyama Dam.