| Otori Dam | |
| Location Map: | Japan |
| Coordinates: | 37.2147°N 139.2139°W |
| Country: | Japan |
| Location: | Tadami |
| Status: | O |
| Construction Began: | 1961 |
| Opening: | 1963 |
| Owner: | Electric Power Development Company |
| Dam Type: | Arch-gravity |
| Dam Height: | 830NaN0 |
| Dam Length: | 1880NaN0 |
| Dam Crosses: | Tadami River |
| Res Capacity Total: | 158000000NaN0 |
| Res Capacity Active: | 50000000NaN0 |
| Res Catchment: | 656.90NaN0 |
| Res Surface: | 890NaN0[1] |
| Plant Hydraulic Head: | Unit 1: 50.80NaN0 Unit 2: 48.10NaN0 |
| Plant Commission: | 1963, 2003 |
| Plant Turbines: | 1 x 95 MW, 1 x 87 MW Kaplan-type |
| Plant Capacity: | 182 MW |
The is a concrete arch-gravity dam on the Tadami River, 170NaN0 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 830NaN0 tall and 1880NaN0 long. Its reservoir has a 158000000NaN0 capacity of which 50000000NaN0 is active (or "useful") for power generation. The reservoir has a catchment area of 656.90NaN0 and surface area of 890NaN0. Of the two generators, Unit 1 has a maximum effective hydraulic head of 50.80NaN0 and Unit 2 is afforded 48.10NaN0. The design flood discharge of the dam is 22000NaN0 and its service spillway is controlled by three tainter gates.[2]