Shobojigawa Minamisawa Dam No. 12
From Dam No. 12 downstream, the overflow notch is cut wider. The site is said to have been supervised by Sato Soichiro (佐藤總一郎), an assistant civil-works technician for the prefecture.
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.
About one hundred and thirty metres below No. 9-1. From this dam downstream the overflow is set wider. The on-site supervisor for this work is said to have been Sato Soichiro (佐藤總一郎), an assistant civil-works technician of the prefecture.
Why It Matters
The system divides among three side-ravines, north, Tanuki and south, each carrying its own line of stone dams, with wire-gabion works to blunt the force of the water. The reliance on many small and medium dams rather than a single giant reflects the sabo engineering of the day.
The stones are coursed diagonally, the tanizumi bond, and mortared between, the nerizumi finish, so the body holds together under pressure. Like the other dams here it is built mainly of rhyolitic welded tuff. The downstream face carries a 3-bu batter.
Intact groups of stone check dams from the 1920s are not common. The 2005 listing set the whole undertaking, a community's long reckoning with landslide and flood, in the frame of cultural heritage.
Seeing It Today
Reaching the dam means walking mountain paths, best avoided after rain or during snowmelt when the stream runs high. Seen from nearby, each block of rhyolitic welded tuff, split and set by hand, still carries the mark of the mason who placed it.
The dam measures 26 metres along its crest and stands 3.0 metres high. It belongs to the Minamisawa branch and was completed in 1927.
- 📍 Plan Your Visit to Yamagata
- Find tours, activities & transport passes near Shohoji River Minamizawa No. 12 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.
- Who supervised the site?
- The work at No. 12 is said to have been overseen by Sato Soichiro (佐藤總一郎), an assistant civil-works technician. This rests on record and tradition rather than firm documentation.
- When were these dams built and listed?
- This one dates to 1927, 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 | 正法寺川南沢第十二号石堰堤 (Shobojigawa Minamisawa Dam No. 12) |
|---|---|
| Location | Shimo-Oginoto, Tendo City, Yamagata Prefecture |
| Designation | Registered Tangible Cultural Property (structure), registered 2005; registration no. 06-0084 |
| Date | 1927 (昭和2年) |
| Form | Gravity-type stone check dam; crest length 26 m, height 3.0 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 — 正法寺川南沢第十二号石堰堤
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00004893
- 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