A Round Reservoir at the Heart of the Plant
The Nagae Water Purification Plant Distribution Reservoir (長江浄水場配水池) is a circular distribution reservoir of 1925 in Nagae, Onomichi City, Hiroshima Prefecture, and was registered as a Registered Tangible Cultural Property (structure) on November 8, 2004 (Agency for Cultural Affairs).
The Agency records a reinforced concrete structure of 584 square metres with a reinforced concrete shelter; registration number 34-0061.
A Round Basin Sharing the Filters' Centre
The Nagae Water Purification Plant Distribution Reservoir is a circular reinforced concrete structure with a radius of 14 metres, set on the same centre as the fan-shaped slow sand filter basin; a central wall divides it in two (Agency for Cultural Affairs).
Filtered water receives a disinfecting solution at a round well in the middle of the reservoir, then winds along two concentric guide walls, which improves the mixing as it flows (Agency for Cultural Affairs).
Why It Was Registered
The Agency registered the Nagae Water Purification Plant Distribution Reservoir as a model of design. A functional idea, making the water meander to mix it better, and the Art Deco shelter are combined in a single round basin.
The Twelve-Sided Shelter
Above the central well stands a reinforced concrete shelter on a twelve-sided plan, which the Agency describes as Art Deco in style.
What to Look For
Look for the twelve-sided shelter over the central well of the Nagae Water Purification Plant Distribution Reservoir, and for the round plan held within the fan of filter basins (Agency for Cultural Affairs; Onomichi City Water and Sewerage Bureau).
Visiting
The Nagae Water Purification Plant Distribution Reservoir lies inside a working water plant, and no official information on public access to the grounds was found. The water bureau says it accepts requests to tour its facilities and describes staff guiding a primary school class around the plant (Onomichi City Water and Sewerage Bureau). Directions and the opening hours of the Onomichi Waterworks Memorial Hall are on the Nagae Water Purification Plant page.
Q&A
- When was the Nagae Water Purification Plant Distribution Reservoir built?
- In 1925 (Agency for Cultural Affairs).
- How large is the Nagae Water Purification Plant Distribution Reservoir?
- It is a circle with a radius of 14 metres, covering 584 square metres (Agency for Cultural Affairs).
- What does the shelter on the Nagae Water Purification Plant Distribution Reservoir look like?
- It is a twelve-sided reinforced concrete structure that the Agency describes as Art Deco in style.
- Can I visit the Nagae Water Purification Plant Distribution Reservoir?
- It is inside a working plant and no public access is announced; the water bureau accepts requests for facility tours.
- When was the Nagae Water Purification Plant Distribution Reservoir registered?
- On November 8, 2004 (Agency for Cultural Affairs).
Basic Information
| Name | Nagae Water Purification Plant Distribution Reservoir (長江浄水場配水池) |
|---|---|
| Location | 3-6-52 Nagae, Onomichi City, Hiroshima Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2004/11/08 (Heisei 16) |
| Quantity | 1 structure |
| Dimensions | Reinforced concrete, 584 m², radius 14 m, with a reinforced concrete shelter |
| Owner | Onomichi City |
| Public Access | Part of a working water plant (no published access to the grounds) |
References
- Nagae Water Purification Plant Distribution Reservoir (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00004410
- Onomichi Waterworks Centennial website (Onomichi City Water and Sewerage Bureau, Japanese)
- https://water-onomichi-anniv100th.jp/
Last verified: 2026.11.09
