Okutadami Dam
The 30th tallest dam in the world
The Okutadami Dam 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.
Dam data from Wikidata (CC0) plus curated additions. Summary from Wikipedia (CC BY-SA).