Shobojigawa Tanukisawa Dam No. 1
At just seven metres across, this is one of the smaller dams in the group, yet it was given a full secondary dam and revetment.
This dam is one of a chain of erosion-control structures built along the Shobojigawa, a stream that runs through the Shimo-Oginoto district of Tendo City, Yamagata, and joins the Kuratsugawa on its way to the Mogami River. After a severe flood struck the valley in 1913, Yamagata Prefecture built a run of stone check dams and current-control works here between 1922 and 1927.
Despite its small size it carries a full secondary dam and bank revetment. A square drainage opening pierces the lower centre of the body. It stands on a right-bank tributary just above the confluence with the main channel.
Why It Matters
The Shobojigawa scheme sets sixteen dams along the north branch, three along the Tanuki ravine and ten along the south branch, together with wire-gabion current-control works. No single dam is large; instead they are strung from upstream to down, catching sediment stage by stage.
It is built by the tanizumi method, stones set diagonally so they interlock, a pattern that stands up well to moving water. The joints are packed with mortar, in the nerizumi manner, binding the body into a single mass. The downstream face carries a 3-bu batter.
In 2005 the Shobojigawa erosion-control facilities were placed on the national register of tangible cultural properties. The listing cites their contribution to the historical landscape of the country, recognising a modern civil-engineering work as heritage that shapes the character of a place.
Seeing It Today
The dam sits along a mountain stream, not at a developed sightseeing spot. Watch your footing, and stay away when the water is high. Look closely at the face of each set stone and the finish of the overflow lip, and the density of hand labour from before mechanisation comes into view.
The dam measures 7.0 metres along its crest and stands 2.4 metres high. It belongs to the Tanukisawa branch and was completed in 1923.
- 📍 Plan Your Visit to Yamagata
- Find tours, activities & transport passes near Shohoji River Tanukizawa No. 1 Stone Dam
- [ Yamadera Temple & Zao Onsen Hot Springs ]
Q&A
- What exactly is a stone check dam?
- It is a low masonry wall built across a mountain stream to trap gravel and sand and to slow the water, reducing the risk of debris flows downstream. These examples are made of dressed stone rather than concrete.
- Can I visit it, and is it free?
- The dams stand on public land along the stream and can be seen from outside at no charge, but there are no visitor facilities, signs or guardrails. Treat it as backcountry and go prepared.
- Why is it so small?
- The Tanukisawa ravine is narrow, and its upper reach neither needed nor allowed a large structure. Small dams were strung together to trap sediment in stages.
- When were these dams built and listed?
- This one dates to 1923, part of works carried out between 1922 and 1927. The whole group was registered as a national tangible cultural property in 2005.
Basic Information
| Name | 正法寺川狸沢第一号石堰堤 (Shobojigawa Tanukisawa Dam No. 1) |
|---|---|
| Location | Shimo-Oginoto, Tendo City, Yamagata Prefecture |
| Designation | Registered Tangible Cultural Property (structure), registered 2005; registration no. 06-0074 |
| Date | 1923 (大正12年) |
| Form | Gravity-type stone check dam; crest length 7.0 m, height 2.4 m; 1 unit |
| Owner | Yamagata Prefecture |
| Access | Mountain stream; no visitor facilities. Open watercourse, viewable from public land. |
References
- National Database of Designated Cultural Properties, Agency for Cultural Affairs — 正法寺川狸沢第一号石堰堤
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00004865
- Tendo City — Registered Tangible Cultural Properties
- https://www.city.tendo.yamagata.jp/tourism/history/tourokubunkazaihoka.html
- Cultural Heritage Online, National Institutes for Cultural Heritage — Yamagata / Tendo
- https://bunka.nii.ac.jp/heritages/region/6/6210
Last verified: 2026.07.03