Lake Okutama
Okutama, Japan
Lake Okutama (Okutama-ko) is in Tokyo and Yamanashi Prefectures in Japan. Lying above the Ogōchi Dam, it is also known as the Ogōchi Reservoir. Lake Okutama is an important source of drinking water for Tokyo.
Reservoir data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).