What Is the Inari River Tenth Sabo Dam?
The Inari River Tenth Sabo Dam (稲荷川第十砂防堰堤, Inarigawa Daijū Sabō Entei) is a concrete gravity erosion-control dam built in 1923 and enlarged in the Showa era, standing on the Inari River in the Akanagi-Hinata and Kamatsusawa area of Nikko City, Tochigi Prefecture; it was registered in 2002 as a Registered Tangible Cultural Property (Structure) of Japan, with effect from 21 August. The national database gives it as 45 meters long and 11 meters high, and it belongs to the national government (Ministry of Land, Infrastructure, Transport and Tourism).
The dam sits about 600 meters above the Third Dam, at the outlet of a narrow gorge in the middle reaches of the Inari River. It is the uppermost of the numbered Inari River dams on the register; the Kamatsusawa Downstream Sabo Dam follows 366 meters farther up. Its registration number is 09-0058, and it was registered as a model of design.
A Dam Rebuilt in Stages
The Inari River Tenth Sabo Dam is no longer in its original form. The Agency for Cultural Affairs records its dates as 1923, with enlargements in 1929, 1932 and 1939. The Nikko Sabo Office has published a photograph of the dam under construction on 1 April 1923.
According to the agency, the dam originally had a 5.2-meter-wide overflow section set vertically on its downstream side. Later enlargements changed that arrangement into the shape seen today. A point where a valley narrows concentrates the flow and takes the full force of debris flows, and conditions like these seem to have demanded repeated reworking of the original design.
The Japan Society of Civil Engineers describes the work differently: a thickening of the downstream face in 1929 and a raising of the crest in 1941, followed by repairs in 2009. It gives the resulting size as 13.1 meters high and 65.5 meters long, figures that do not match the national database.
Why the Inari River Tenth Sabo Dam Was Registered
The Agency for Cultural Affairs values the Inari River Tenth Sabo Dam as a record of erosion control that has kept working under harsh natural conditions. A Taisho-era core with Showa-era additions layered over it sums up the story of the Inari program in a single structure: damage, repair, and more repair. Its face is laid in diagonal Tanizumi masonry with mortared Nerizumi joints, like the other dams.
What to Look for at the Inari River Tenth Sabo Dam
The Inari River Tenth Sabo Dam is an outdoor facility with no admission fee, viewed from the riverside path. Climbing onto the dam is not allowed.
It lies about 600 meters uphill from the Third Dam, the longest walk between any two of the registered dams. It stands noticeably taller than the four dams below, and seen together with the narrowing walls of the valley, it makes clear that this is where the flow gathers. Look closely at the stone face to see whether you can pick out where later work was added. From here you can also continue upstream to the two Kamatsusawa dams. Directions to the dams are on the Inari River Sabo Dams page.
- 📍 Plan Your Visit to Tochigi
- Find tours, activities & transport passes near Inari River Tenth Sabo Dam
- [ Nikko Toshogu Shrine & Kegon Falls Day Trip ]
Q&A
- When was the Inari River Tenth Sabo Dam built?
- It was built in 1923, and the Agency for Cultural Affairs records enlargements in 1929, 1932 and 1939.
- How big is the Inari River Tenth Sabo Dam?
- The national database gives 45 meters long and 11 meters high. The Japan Society of Civil Engineers gives 65.5 meters long and 13.1 meters high, so the figures differ between sources.
- Why was the Inari River Tenth Sabo Dam enlarged?
- It stands at the outlet of a narrow gorge, where flood water and debris flows are concentrated, which appears to be why the original design needed reworking. The enlargements changed the original overflow section into its present form.
- Where is the Inari River Tenth Sabo Dam?
- On the Inari River in Nikko, about 600 meters above the Third Dam, at the mouth of a narrow gorge in the middle reaches. The Kamatsusawa Downstream Sabo Dam is 366 meters farther upstream.
- Can I visit the Inari River Tenth Sabo Dam, and is there a fee?
- Yes, you can view it from the riverside path free of charge. It is a working dam, so you cannot climb onto it. The approach from the lower dams is a steady climb, so allow plenty of time.
Basic Information
| Name | Inari River Tenth Sabo Dam (稲荷川第十砂防堰堤) |
|---|---|
| Location | Aza Akanagi-Hinata and Kamatsusawa, Oaza Nikko, Nikko City, Tochigi Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered in 2002 |
| Quantity | 1 structure |
| Dimensions | 45 meters long, 11 meters high (concrete gravity dam; national database figures) |
| Owner | Government of Japan (Ministry of Land, Infrastructure, Transport and Tourism) |
| Public Access | Outdoor erosion-control facility; exterior viewable from the riverside path (no fee) |
References
- Agency for Cultural Affairs, Database of National Cultural Properties: Inari River Tenth Sabo Dam
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00002884
- Cultural Heritage Online: Inari River Tenth Sabo Dam
- https://online.bunka.go.jp/heritages/detail/115764
- MLIT Kanto Regional Development Bureau, Nikko Sabo Office: History of the Registered Sabo Dams (Japanese)
- https://www.ktr.mlit.go.jp/nikko/nikko00038.html
- Japan Society of Civil Engineers, Kanto Branch: Sabo Dams of the Inari River Basin, Nikko (Japanese)
- https://www.jsce.or.jp/branch/kanto/04_isan/h26/h26_3.html
- Tochigi Prefecture Cultural Properties: Inari River Tenth Sabo Dam (Japanese)
- https://bunkazai.pref.tochigi.lg.jp/cultural/%E3%80%90%E7%A8%B2%E8%8D%B7%E5%B7%9D%E7%AC%AC%E5%8D%81%E7%A0%82%E9%98%B2%E5%A0%B0%E5%A0%A4%E3%80%91/
Last verified: 2026.10.01
