A Mountain-Stream Dam of 1932
The Yamanokami Dam (山ノ神堰堤) is an erosion-control dam of 1932 in Horiyamashita and Togawa, Hadano City, Kanagawa Prefecture, and was registered as a Registered Tangible Cultural Property (structure) on March 18, 2003 (Agency for Cultural Affairs).
The Agency records a gravity dam 32 metres long and 13 metres high, with a secondary dam and revetment on the upstream right bank; registration number 14-0076.
In a Narrow Reach of the Minase River
The Yamanokami Dam was built where the valley narrows in the middle reach of the Minase River, which rises on Mount Tonodake (Agency for Cultural Affairs). It was a project carried out directly by the Home Ministry.
According to Kanagawa Prefecture, 8 historic erosion-control dams in the prefecture are Registered Tangible Cultural Properties, and the Yamanokami Dam is one of those on the Minase River in the Kaname River system.
Why It Was Registered
The Yamanokami Dam was registered as a structure that would not be easy to reproduce. Provision for irrigation water is built into the very shape of the dam.
What to Look For
The dam is a wet-masonry gravity structure, with the upstream face battered at 5 in 10 and the downstream face at 2 in 10 (Agency for Cultural Affairs).
At the right-bank end of the spillway is an irrigation channel. To bring its water to the front of the dam, the right side of the dam body projects in a tube-like form, making use of the existing bedrock (Agency for Cultural Affairs). That projection on the right bank is the feature to look for at the Yamanokami Dam.
Visiting
The Yamanokami Dam is a river structure owned by Kanagawa Prefecture, and no official information on viewing or access was found. It lies in Horiyamashita and Togawa, Hadano City (Agency for Cultural Affairs). Rivers can rise quickly, so take care if you go near.
Q&A
- When was the Yamanokami Dam built?
- In 1932, as a direct project of the Home Ministry (Agency for Cultural Affairs).
- Where is the Yamanokami Dam?
- In a narrow reach of the Minase River in Hadano City.
- How big is the Yamanokami Dam?
- 32 metres long and 13 metres high (Agency for Cultural Affairs).
- What is unusual about it?
- An irrigation channel at the right end of the spillway, fed through a tube-like projection of the dam body.
- When was the Yamanokami Dam registered?
- On March 18, 2003 (Agency for Cultural Affairs).
Basic Information
| Name | Yamanokami Dam (山ノ神堰堤) |
|---|---|
| Location | Horiyamashita and Togawa, Hadano City, Kanagawa Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2003/03/18 (Heisei 15) |
| Quantity | 1 structure |
| Dimensions | Concrete gravity dam, 32 metres long, 13 metres high, with secondary dam and upstream right-bank revetment |
| Owner | Kanagawa Prefecture |
| Public Access | No public access information |
References
- Yamanokami Dam (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00003206
- Historic Erosion-Control Structures of Kanagawa (Kanagawa Prefecture, Japanese)
- https://www.pref.kanagawa.jp/docs/jy2/cnt/f420226/p27240.html
Last verified: 2026.10.14