What the Kamakurazawa River No. 8 Sabo Dam Is
The Kamakurazawa River No. 8 Sabo Dam is a stone check dam on the Kamakurazawa River in Yoshizato, Minamiuonuma City, Niigata Prefecture, completed in 1930 and entered on the national register as a Registered Tangible Cultural Property structure on 4 August 2015.
At 33 meters long and 3.9 meters high, it is the tallest of the eight registered structures. It stands about 40 meters above the No. 6 Sabo Dam and is the uppermost of the three dams placed above the bend in the main channel.
The national database is unusually specific about how this one was shaped: the downstream face is battered at two tenths, and the crest is built thick. It adds that the Kamakurazawa River No. 8 Sabo Dam survives in the best condition of all the prewar sabo structures on this stream, and that it now stands among greenery that returned once the bed of the torrent stopped moving.
Design Written into the Section
Registration came under the criterion of contributing to the historic landscape of the country, recommended on 13 March 2015 and entered on 4 August that year as registration number 15-0416.
A batter of two tenths means the downstream face leans out two units horizontally for every ten units of height. Rather than rising vertically, the body widens as it descends, spreading its own weight across a broader base. For a gravity dam this is standard practice, but few records of the period state the figure outright.
Thickening the crest follows the same logic. The crest is where water and sediment pass over, taking the abrasion and the impact, and extra thickness leaves material to spare in the place that wears fastest. Those two dimensions are what carry the 3.9 meters of height, the greatest among the eight. The good condition in which the Kamakurazawa River No. 8 Sabo Dam has survived rests on that margin built into the section.
Standing in Recovered Greenery
The reference to returning vegetation says as much about the scheme as any measurement. In a valley whose bed keeps cutting downward, the slopes on either side lose their footing, slip, and never carry mature trees. Fix the level of the bed and the slopes settle, and over decades the plants come back. The green around the Kamakurazawa River No. 8 Sabo Dam is an outcome of the engineering, not a backdrop to it.
Being the best preserved of the eight, it shows few missing stones and few open joints, and its edges stay crisp. A height of 3.9 meters is enough to look up at, and the path of the water from the overflow section down the face is easy to follow. The batter itself only reads from the side, so it is worth moving round to a position where the flank of the body is visible.
From here to the No. 9 Sabo Dam is about 190 meters, the longest gap in the whole sequence. The run of closely spaced dams ends at this point.
Visiting the Kamakurazawa River No. 8 Sabo Dam
This is a working outdoor structure with no interior. Viewing is from the bank, free of charge, with no reception and no restriction on photography.
To see the shape of the section, look for an oblique angle from downstream where the flank of the dam body shows; a square-on view hides both the batter and the thickness of the crest. Trees have grown up around the structure, so the whole body is easier to take in once the leaves are down, though that season overlaps with the snow.
Stay out of the streambed. The valley cannot be reached in winter, so plan for roughly May to November. Directions and the parking situation are set out on the Kamakurazawa River Sabo Facilities page.
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Q&A
- Can the Kamakurazawa River No. 8 Sabo Dam be visited?
- Yes, from the bank at any time and without charge. There is no car park or footpath, and entering the streambed is dangerous.
- What does the two-tenths batter on the Kamakurazawa River No. 8 Sabo Dam mean?
- The downstream face slopes two units outward for every ten units of height, so the body widens towards the base and carries its own weight over a broader footing.
- How large is the Kamakurazawa River No. 8 Sabo Dam?
- 33 meters long and 3.9 meters high, the greatest height among the eight registered structures. It was completed in 1930 and registered as a Registered Tangible Cultural Property (structure) under number 15-0416.
- What condition is the Kamakurazawa River No. 8 Sabo Dam in?
- The national database calls it the best preserved of the prewar sabo structures on this stream. Its stonework remains sharp-edged and it sits well within the vegetation that has grown back around it.
- How far is the next dam from the Kamakurazawa River No. 8 Sabo Dam?
- About 190 meters upstream to the No. 9 Sabo Dam, the longest interval in the sequence. Downstream, the No. 6 Sabo Dam is only 40 meters away.
Basic Information
| Name | Kamakurazawa River No. 8 Sabo Dam (鎌倉沢川第八号堰堤) |
|---|---|
| Location | Yoshizato, Minamiuonuma City, Niigata Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2015/8/4 (Heisei 27) |
| Quantity | 1 site |
| Dimensions | 33 meters long, 3.9 meters high |
| Owner | Niigata Prefecture |
| Public Access | Working outdoor structure; exterior visible from the bank at any time, no interior access |
References
- National Cultural Properties Database: Kamakurazawa River No. 8 Sabo Dam (Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00010581
- Sabo Facilities on the Kamakurazawa River Entered on the National Register (Niigata Prefecture, Minamiuonuma Regional Promotion Bureau)
- https://www.pref.niigata.lg.jp/sec/minamiuonuma_seibi/1356827806289.html
- Registered Cultural Properties of Minamiuonuma City (Minamiuonuma City Board of Education)
- https://www.city.minamiuonuma.niigata.jp/docs/890.html
Last verified: 2026.09.12
