Shionokawa Fourth Dam

A Thick Dam at the Mouth of the Shionokawa

The Shionokawa Fourth Dam (塩の川第四堰堤, Shionokawa Daiyon Entei) is a gravity concrete sabo dam built in 1956 at the lowest reach of the Shionokawa, a left-bank tributary of the Arakawa River, near the confluence in Tsuchiyu Onsen-cho, Fukushima City, Fukushima Prefecture, and it was registered as a Registered Tangible Cultural Property on July 8, 2008.

The national record gives a crest length of 56 meters and a height of 16 meters, the tallest of the fifteen Arakawa dams. It is registration number 07-0103 and, together with the Shionokawa First Dam about a kilometer upstream, guards the tributary.

Why the Shionokawa Fourth Dam Was Registered

The Shionokawa Fourth Dam was registered under the criterion for structures that contribute to the historic landscape of the country. Its faces are battered at 0.45 to 1 upstream and 0.2 to 1 downstream, and the downstream face is laid in diagonal Tanizumi masonry.

What the Agency for Cultural Affairs singles out is the thickness of the crest, made 3.0 meters wide to match the planned sediment storage. Its job of holding back the Shionokawa's debris just before the confluence shows in the bulk of the dam.

What to Look For

Study the downstream face, where diagonally set stones draw a diamond pattern across the full 16-meter height.

From the side you can also sense the thickness of the crest. At 3.0 meters it is heavy for a dam on a narrow tributary, sized for the volume of sediment the stream was expected to carry.

Visiting the Shionokawa Fourth Dam

The Shionokawa Fourth Dam is a working erosion-control structure. There is no fee; you view it from nearby, and climbing on the dam or going down to the riverbed is not allowed. After rain the river can rise suddenly, so keep away from the banks. Directions are on the Arakawa River Sabo Dams page.