Iwado Segi Cylindrical Water Divider

A 1927 Cylindrical Water Divider

The Iwado Segi Cylindrical Water Divider (岩堂セギ分水口) is a reinforced-concrete cylindrical water divider built in 1927 at Ushiku, Enzan, Koshu City, Yamanashi Prefecture, and registered as a Registered Tangible Cultural Property (structure) on May 2, 2017. It splits the water of the Bingushi River into three equal parts for the surrounding alluvial fan (Agency for Cultural Affairs, Yamanashi Prefecture).

The Agency for Cultural Affairs records reinforced concrete with an area of 9.6 square metres; registration number 19-0090, owned by Koshu City. Koshu City notes that it is managed by the local Hanazono district.

At the Pivot of the Fan

According to Yamanashi Prefecture, water is drawn from the Bingushi River near the JR Chuo Line viaduct and divided at Iwado, the pivot of an alluvial fan spreading north and west. Of the three channels, one runs west to the Maeda settlement and two north to the Ushiku and Nishinohara districts.

Koshu City counts the Iwado Segi Cylindrical Water Divider among the most representative water-management structures of the area and put up an information board after its registration (Koshu City).

Value as a Registered Cultural Property

The Iwado Segi Cylindrical Water Divider was registered as a structure that has become a model of design. Built to share farm and household water accurately, it preserves from the early Showa era a cylindrical divider whose fair sharing can be seen at a glance (Agency for Cultural Affairs, Koshu City).

What to Look For

The Agency for Cultural Affairs describes three concentric cylinders. By siphon action, water wells up in the small central cylinder, fills the middle cylinder, passes through 12 openings in its wall in three equal shares, and flows from the outer cylinder into three channels.

At the Iwado Segi Cylindrical Water Divider you can watch water rise from the small cylinder and divide into three as it passes from the middle to the outer ring (Koshu City).

Visiting

The Iwado Segi Cylindrical Water Divider is an outdoor irrigation structure still in local use, at 1520 Kaminodan, Ushiku, Enzan, Koshu City. View it from outside and take care near the channels. Enquiries go to the cultural properties section of the Koshu City Board of Education (0553-32-5076).