The is a river system in the Hokuriku region of Honshu, Japan. It is also called the Aga River or the Ōkawa River in Fukushima. It is designated as a Class A river. Approximately 560,000 people live in the basin area.
Agano is connected to the adjacent Shinano River by the long Koagano channel.
There are several hydroelectric power plants on the Agano River:
- Inawashiro Power Plant (107.5 MW), constructed in several stages in 1899–1940. It was the site of Japan's first high-voltage, long-range power transmission line.
- Numazawanuma Power Plant (43.7 MW), constructed in 1952. It was the first pumped-storage power plant in Japan.
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Agano River near Kitakata (3848211488).jpg|Agano River near Kitakata
Agano River.jpg|Agano River in Kōnan-ku, Niigata, 5/5/2007
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