Tokuyama Dam

Tokuyama Damlargest reservoirIbigawadrowned villagerockfill dam

Gifu · Ibigawa

35.6757°N, 136.4572°E

Tokuyama holds 660 million cubic metres of water, the largest reservoir capacity of any dam in Japan — roughly twice the volume of Lake Hamana. It is a rockfill dam, 161 metres high and 427 metres along the crest, completed in 2008 on the upper Ibi river after a construction programme that ran for decades.

Under the water is Tokuyama village, which was dissolved and its residents relocated so the reservoir could be filled. That fact sits behind the scenery and is why the visit is not simply about engineering scale. The crest is open as a walkway, there is a viewpoint over the whole structure, and the road up follows the drowned valley. It is about eighty minutes from Ogaki through increasingly empty country.

Essential Information

Opening Hours

Site accessible in daylight | Facilities generally 9:00 AM – 5:00 PM

Closed: Approach road affected by winter conditions

Entrance Fee

Free

Best Season

Late October–November for autumn colour | Late April–May for fresh green

Visit Duration

60–90 minutes

Getting There

Access Information

Kaida 448, Ibigawa, Ibi District, on the upper Ibi river. About 80 minutes by car from Ogaki IC on the Meishin Expressway via Routes 303 and 417. Free to visit; the dam crest is open as a walkway and there is a viewpoint over the structure. Facilities in the area generally operate 9:00 AM – 5:00 PM. Winter conditions affect the approach road.

Insider Guide

Premium

**A village is under the water.** Tokuyama was dissolved and its people moved so the reservoir could be filled. Knowing that changes what the view is. **Largest capacity in Japan.** 660 million cubic metres, about twice Lake Hamana. The number only means something from the crest, which is 427 metres long and open to walk. **Eighty minutes from Ogaki.** Through progressively emptier country on Route 417. Fuel and food before the last stretch rather than after. **Rockfill, not concrete.** The face is banked stone rather than a poured wall, which is why it reads as a mountainside rather than a structure until you are on it. **Winter closes things.** This is deep-snow country in the Ibi headwaters and the approach is affected. Check conditions between December and March.

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