Arakawa Sixth Dam

What the Arakawa Sixth Dam Is

The Arakawa Sixth Dam (荒川第六堰堤, Arakawa Dai-roku Entei) is a gravity-type concrete sabo dam built in 1950 on the Arakawa River at Kamikawahara, Tsuchiyu Onsen-cho, in Fukushima City, Fukushima Prefecture, and registered as a Registered Tangible Cultural Property (structure) of Japan on March 7, 2008. It is 54 meters long and 12 meters high, with a Sub-dam (sub-dam) downstream, and Fukushima City lists the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) as the owner.

One of the 15 registered Arakawa River Sabo Dams, it stands about 900 meters upstream of the Arakawa First Dam, just below the mouth of a side stream named 産ヶ沢, with the Arakawa Second Dam some 1,600 meters farther up. It was registered as a Registered Tangible Cultural Property in 2008 under number 07-0087.

Resuming Work on the Main River After the War

Sort the main-river dams in the group by completion year and the Arakawa Sixth Dam comes fifth. The prewar First (1937), Second (1938) and Third (1940) are followed by Kawakami First Dam (1946), whose construction straddled the war, and then by the Sixth in 1950. After that the pace quickens: the Seventh in 1951, the Eighth in 1952 and the Fifth in 1954.

The Sixth sits below the spa town, between the First and the Second. It was the postwar addition to the reach between those two prewar dams, placed right below the confluence with that side stream.

Two Faces, Two Kinds of Stone

The Arakawa Sixth Dam uses different stonework on each face. The Agency for Cultural Affairs records the upstream face as cobble masonry and the downstream face as Nunozumi. Cobble masonry uses rounded river stones; nunozumi uses stones of matching height laid so the horizontal joints run straight. The slopes are the group's standard 1 to 0.45 upstream and 1 to 0.2 downstream.

On a sabo dam the upstream face is the side that disappears as sediment piles up behind it. Pairing a cobble face there with a tidy coursed face on the side people see suggests the builders matched the finish to each face's role. The Arakawa Seventh Dam, finished a year later, uses the same combination.

Downstream stands a sub-dam of the same type. It absorbs the energy of water falling off the main dam so the bed at the main dam's foot is not dug out, and the two work as a pair.

Seeing the Arakawa Sixth Dam

The Arakawa Sixth Dam is a working sabo structure. Viewing is free from the surrounding ground; walking on the dam or entering the riverbed is not possible.

The arrangement to notice is the main dam and its sub-dam set one behind the other. From downstream, the low sub-dam sits in front of the coursed face of the main dam with a plunge space between them. The other detail is the downstream masonry itself, coursed rows climbing the 12-meter face in even steps.

Keep away from the banks after rain, when the river rises fast. Directions are on the Arakawa River Sabo Dams page.