Ushibuse River Erosion Control Works

Ushibuse River Erosion Control Works

The Ushibuse River Erosion Control Works (牛伏川砂防施設) on the Ushibuse River in the Chikuma mountains south-east of Matsumoto, Nagano Prefecture, include a stepped stone channel of 1917, designated an Important Cultural Property in 2012, and four check dams of 1886 and 1887, the Nos. 2 to 5, registered as Registered Tangible Cultural Properties in 2021 (Agency for Cultural Affairs). All are owned by Nagano Prefecture.

The Agency notes that the dams were built directly by the Home Ministry as part of flood control on the Shinano River system, and that the stepped channel is the core of the Ushibuse works, which restored the slopes through planting.

The Five Structures

The stepped channel sets nineteen bed sills along 141 metres of stone channel so that the whole forms a staircase, modelled on the channels used to tame mountain torrents in the Alps (Agency for Cultural Affairs). Nagano Prefecture calls it the French-style stepped channel.

The Nos. 2 to 5 check dams are stone gravity dams of great boulders laid dry at a gentle slope, 18 to 25 metres long and 6.5 to 8.2 metres high (Agency for Cultural Affairs). Meiji dams and a Taisho channel together tell the story of erosion control in a single valley. Each structure is described on its own page.

Visiting

According to Nagano Prefecture's Matsumoto Construction Office, anyone may visit the works freely, on seven walking courses. They are about 20 minutes by car from Matsumoto Station, with parking at Gofukuji temple (about 20 cars) and elsewhere. Some spots are dangerous, so take care.