A Small Weir Built to Be Overtopped
The Heisakubara Power Station Endobara River Intake Weir (平作原発電所遠藤原川取水堰堤, Endōbara River) is an overflow-type concrete gravity weir built in 1928 on the Endōbara River in Kamisaibara, Kagamino Town, Okayama Prefecture, and registered as a Registered Tangible Cultural Property on 29 November 2006.
At 8.2 metres long and 2.4 metres high, it is one of the smaller pieces of the system. The water it diverts runs along the Endōbara channel and merges with the channel coming from the Endō River.
Tapping a modest side stream like this one shows how the planners tried to gather every usable flow in the valley for generation.
A Long Apron for a Short Weir
The Heisakubara Power Station Endobara River Intake Weir was registered as a structure that contributes to the historic scenery of the country.
It is an overflow weir, meaning water is expected to spill across its crest as a matter of routine, and the downstream face slopes at 0.8 to 1. The Agency for Cultural Affairs highlights the concrete apron, 7.5 metres long, cast as one piece with the weir to stop falling water from scouring the riverbed. For a weir only 2.4 metres high, that is a generous apron, which suggests the designers treated overtopping as the normal state of affairs.
Two sluice gates stand on the right bank, their surfaces finished in mortar. In a very compact form, the structure handles intake, overflow and protection of the bed.
What to Look For
The apron is the thing to see. Water that tops the weir runs straight onto the long concrete floor and returns to the river without digging into its bed. Keep the ratio of height to apron length in mind and it becomes clear what the builders feared most.
The mortar-rendered gates are worth a look too. Much of this power station is faced in stone, so the smooth rendered finish here stands out.
The Endōbara River settling basin follows directly below on the right bank; follow the handoff of water between intake and basin across the slope.
Visiting the Endobara River Intake Weir
The Heisakubara Power Station Endobara River Intake Weir is a working intake run by Chugoku Electric Power, and no visitor facilities are advertised. The weir, the gates and any gated or fenced area are closed, so you can only see the exterior from places where access is permitted.
It lies in the mountains of the Endō district. Because the weir is built to overflow, the stream can rise fast after rain; stay back from the water, and watch for snow in winter.
The company's page gives no restriction on photographing exteriors, but you cannot enter operational areas to take pictures.
- 📍 Plan Your Visit to Okayama
- Find tours, activities & transport passes near Heisakubara Power Station Endobara River Intake Weir
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Q&A
- What is the Heisakubara Power Station Endobara River Intake Weir?
- It is an overflow-type concrete gravity weir built in 1928 to divert water from the Endōbara River for Heisakubara Power Station. It became a Registered Tangible Cultural Property in 2006.
- How large is the Heisakubara Power Station Endobara River Intake Weir?
- It is 8.2 metres long and 2.4 metres high, with a 7.5-metre concrete apron built in one piece on its downstream side.
- Where does water from the Heisakubara Power Station Endobara River Intake Weir go?
- It runs along the Endōbara channel and joins the channel from the Endō River, becoming part of the power station's water route.
- Can I visit the Heisakubara Power Station Endobara River Intake Weir?
- You can see the exterior from places where access is allowed. The weir and the operational areas are closed because the facility is in use.
- How do you pronounce the name of the Heisakubara Power Station Endobara River Intake Weir?
- Heisakubara is read hay-sah-koo-ba-ra and Endōbara is read en-doh-ba-ra. The official Japanese reading of the full name is Heisakubara Hatsudensho Endōbaragawa Shusui Entei.
Basic Information
| Name | Heisakubara Power Station Endobara River Intake Weir |
|---|---|
| Location | Endo area, Kamisaibara, Kagamino Town, Tomata District, Okayama Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2006/11/29 (Heisei 18) |
| Quantity | 1 |
| Dimensions | Crest length 8.2 metres, height 2.4 metres |
| Owner | Chugoku Electric Power Co., Inc. |
| Public Access | Exterior viewing only; operational areas closed |
References
- Agency for Cultural Affairs, Database of National Cultural Properties: Heisakubara Power Station Endobara River Intake Weir
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00006048
- Agency for Cultural Affairs, Database of National Cultural Properties: Heisakubara Power Station Endobara River Settling Basin
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00006049
- Agency for Cultural Affairs, Database of National Cultural Properties: Heisakubara Power Station Endo River Intake Weir
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00006045
- Chugoku Electric Power: History of Heisakubara Power Station (Japanese)
- https://www.energia.co.jp/isan/heisakubara_history.html
- Chugoku Electric Power: Heisakubara Power Station, Historic Electric Power Heritage (Japanese)
- https://www.energia.co.jp/isan/heisakubara.html
- Kagamino Town Tourism: Lake Onbara (Japanese)
- https://www.kagamino.holiday/spot/entry-322.html
Last verified: 2026.09.25
