Masudagawa Dam

Overview

Masudagawa Dam is a flood-control dam built on the middle course of the Masuda River, a class-2 river in Masuda City, Shimane Prefecture. Standing 48 meters high with a crest length of 169 meters, this concrete gravity dam is a so-called hole-in-the-middle (flow-through) dam, with its main spillway set at the riverbed. It is among the largest completed dams of its kind in Japan, and its reservoir was named Hidamari Lake through a local public appeal. It is a place to quietly enjoy a waterscape where flood control and nature come together.

Highlights

• ●A commanding concrete gravity structure, 48 meters high with a 169-meter crest
• ●A flow-through (hole-in-the-middle) dam among the largest completed of its kind in Japan
• ●The calm waterside of Hidamari Lake, named by local public appeal
• ●Quiet scenery on the middle Masuda River where flood control and nature coexist

History

Construction of Masudagawa Dam began in 1973 and was completed in 2005. Dedicated to flood control, its flow-through design places the main spillway at the bottom of the river, so in normal times it lets the current pass straight downstream. It is regarded as the largest completed dam of its type in Japan and is known as an advanced example that balances environmental care with flood-control function. For detailed specifications and whether visits are permitted, please check the official information from Shimane Prefecture.

Map

34.6728, 131.9011 · Wikidata

Suggested itinerary

1. 1Drive up the Masuda River from the direction of JR Masuda Station to the dam
2. 2View the dam body up close and observe its flow-through design
3. 3Enjoy the gentle scenery at the waterside of Hidamari Lake
4. 4On the way back, stop along the lower Masuda River to sense the connected basin

Did you know?

💡 Because it is a flow-through (hole-in-the-middle) dam that normally does not store water, it shows its true strength only during floods. The reservoir's name, Hidamari Lake, meaning a sunny, sheltered spot, was chosen through a public appeal in the local community.

Nearby spots