Tamagawa Dam

Overview

Tamagawa Dam is a 100-meter-high concrete gravity dam built on the Tamagawa, a river of the Omono River system, in Semboku City, Akita Prefecture. Managed directly by the Tohoku Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism, it is the largest dam in the entire Omono River system. The reservoir it created was named Lake Hosen, and its surface, spread among the mountains, is a favorite destination for drives and nature walks.

Highlights

• ●A 100-meter-high concrete gravity dam
• ●The largest dam in the Omono River system
• ●The mountain-cradled surface of the reservoir Lake Hosen
• ●The rare mission of neutralizing strongly acidic water

History

Tamagawa Dam was built as a specified multipurpose dam serving flood control for the Tamagawa and Omono rivers, water supply for Akita City and the Akita Plain, and, notably, improvement of water quality by neutralizing the strongly acidic water originating from the upstream Tamagawa Onsen. Its role of confronting the water once called Tamagawa poison water and bringing it closer to neutral stands out even among the dams of Japan.

Map

39.8309, 140.6403 · Wikidata

Suggested itinerary

1. 1Arrive at Tamagawa Dam and take in the might of the gravity dam up close
2. 2Enjoy the mountain scenery from the shore of Lake Hosen
3. 3Reflect on the dam's roles of flood control, water supply, and water improvement
4. 4Tour any viewing facilities and nearby sights after checking official information

Did you know?

💡 At 100 meters high, it is the largest dam in the Omono River system. Beyond the usual roles of flood control and water supply, its major purpose of improving water quality by bringing strongly acidic river water toward neutral is a defining trait of Tamagawa Dam. The lovely name of its reservoir, Lake Hosen, is one more pleasure of visiting this place.

Nearby spots