What the Kamakurazawa River No. 9 Sabo Dam Is
The Kamakurazawa River No. 9 Sabo Dam is a mortared stone check dam on the Kamakurazawa River in Yoshizato, Minamiuonuma City, Niigata Prefecture, completed in 1932 and entered on the national register as a Registered Tangible Cultural Property structure on 4 August 2015.
It is 13 meters long and 3.0 meters high. That length is the shortest of the eight registered structures, less than a third of the No. 1 Sabo Dam downstream, yet the height is a full three meters, which gives this dam the most compressed proportions in the group.
The ground explains the dimensions. According to the Agency for Cultural Affairs, the body of the Kamakurazawa River No. 9 Sabo Dam expresses the form of a rock-walled narrows. Bedrock is exposed on both banks here and the valley pinches in, so thirteen meters was all it took to cross the stream. The shape of the dam is a record of how wide the valley is at that point.
Top of the Prewar Series
Registration was made 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 15-0417.
This dam stands at the head of the series built on the Kamakurazawa River before the war. It lies about 190 meters above the No. 8 Sabo Dam, the widest interval among the eight. The line of dams that has been ticking past at roughly 40-meter intervals since the No. 5 opens out here and then stops.
Completed in 1932, it was also the last dam built. Work afterwards moved back downstream, closing in 1935 with the No. 23 Ground Sill. Securing the head of the valley first and only then returning to the lower junction gives the nine-year project its shape.
A Wide Notch and Andesite on the Diagonal
The overflow section here has been kept generously wide. Widening the spill across a body only 13 meters long lets the water fall as a thin sheet rather than concentrating on one part of the structure. In a narrow reach, where the current runs faster, shaping the overflow carefully earns its keep.
The face is andesite laid on the diagonal in the bond called tanizumi, with the interior mortared solid. Because the joints cross at an angle, the pattern registers even on a short body. The No. 2 Sabo Dam downstream uses the same andesite and the same bond across 32 meters; here the same technique is compressed into 13. Comparing the two shows how a single method adapts to the width of the valley.
Look at the rock on either bank as well. The wings of the Kamakurazawa River No. 9 Sabo Dam land on stone rather than soil, which is part of why this spot was chosen: a dam founded directly on bedrock is far less likely to shift.
Visiting the Kamakurazawa River No. 9 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.
As the uppermost of the eight, it is the end of the walk for anyone working upstream. The 190 meters from the No. 8 Sabo Dam pass with no structure in sight, so use the stretch to watch the valley narrow. The narrows leave little room to stand, and there is no need to press towards the water; what can be seen from the road is enough.
Stay out of the streambed, where levels rise quickly in a confined reach. Snow closes the valley in winter, so plan for roughly May to November. Directions and the parking situation are covered on the Kamakurazawa River Sabo Facilities page.
- 📍 Plan Your Visit to Niigata
- Find tours, activities & transport passes near Kamakurazawa River No. 9 Sabo Dam
- [ Sado Island & Echigo-Yuzawa Ski Resort Tours ]
Q&A
- Can the Kamakurazawa River No. 9 Sabo Dam be visited, and is there a charge?
- It can be seen from the bank at any time, free of charge. No car park or footpath has been provided, and the streambed should not be entered.
- Why is the Kamakurazawa River No. 9 Sabo Dam so short?
- It was built where bedrock is exposed on both banks and the valley narrows, so thirteen meters was enough to span the stream. The dam records the width of the gorge at that point.
- Where does the Kamakurazawa River No. 9 Sabo Dam sit in the sequence?
- At the top of the prewar series on this stream. The No. 8 Sabo Dam is about 190 meters downstream, the longest gap between any two of the eight structures.
- How is the Kamakurazawa River No. 9 Sabo Dam built, and when?
- As a mortared dam faced in andesite laid on the diagonal, 13 meters long and 3.0 meters high, completed in 1932 and registered as a Registered Tangible Cultural Property (structure) under number 15-0417.
- Why is the overflow section of the Kamakurazawa River No. 9 Sabo Dam so wide?
- A wide spill lets the water fall as a thin sheet instead of loading one part of the structure. That matters most in a narrow reach, where the current is already moving quickly.
Basic Information
| Name | Kamakurazawa River No. 9 Sabo Dam (鎌倉沢川第九号堰堤) |
|---|---|
| Location | Yoshizato, Minamiuonuma City, Niigata Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2015/8/4 (Heisei 27) |
| Quantity | 1 site |
| Dimensions | 13 meters long, 3.0 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. 9 Sabo Dam (Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00010582
- 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
