Otori Dam

The Otori Dam (大鳥ダム, Ōtori damu) is a concrete arch-gravity dam on the Tadami River, 17 km (11 mi) southwest of Tadami in Fukushima Prefecture, Japan. The primary purpose of the dam is hydroelectric power generation and it supports a 182 MW power station. The power station contains two Kaplan turbine-generators. Unit 1 (95 MW) was commissioned on 20 November 1963 while Unit 2 (87 MW) was commissioned on 7 June 2003 as part of a power plant expansion project that included an additional 200 MW generator at Okutadami Dam upstream. The dam is 83 m (272 ft) tall and 188 m (617 ft) long. Its reservoir has a 15,800,000 m³ (12,809 acre⋅ft) capacity of which 5,000,000 m³ (4,054 acre⋅ft) is active (or "useful") for power generation. The reservoir has a catchment area of 656.9 km² (254 sq mi) and surface area of 89 ha (220 acres). Of the two generators, Unit 1 has a maximum effective hydraulic head of 50.8 m (167 ft) and Unit 2 is afforded 48.1 m (158 ft). The design flood discharge of the dam is 2,200 m³/s (77,692 cu ft/s) and its service spillway is controlled by three tainter gates.[2]

Otori Dam
The dam in 1976
Location of Otori Dam in Japan
Country	Japan
Location	Tadami
Coordinates	37°12′53″N 139°12′50″E
Status	Operational
Construction began	1961
Opening date	1963
Owner(s)	Electric Power Development Company
Dam and spillways
Type of dam	Arch-gravity
Impounds	Tadami River
Height	83 m (272 ft)
Length	188 m (617 ft)
Reservoir
Total capacity	15,800,000 m3 (12,809 acre⋅ft)
Active capacity	5,000,000 m3 (4,054 acre⋅ft)
Catchment area	656.9 km2 (254 sq mi)
Surface area	89 ha (220 acres)[1]
Power Station
Commission date	1963, 2003
Hydraulic head	Unit 1: 50.8 m (167 ft) Unit 2: 48.1 m (158 ft)
Turbines	1 x 95 MW, 1 x 87 MW Kaplan-type
Installed capacity	182 MW