The Generator House with a Pitched Roof
The Former Nakajima Water Purification Plant Standby Generator Room Building (旧中島浄水場予備発電機室棟) is the standby generator room of a water purification plant of 1927 in Suidocho, Nagaoka City, Niigata Prefecture, and was registered as a Registered Tangible Cultural Property (structure) on December 24, 2013 (Agency for Cultural Affairs). In romanised Japanese it is Kyū Nakajima Jōsuijō Yobi Hatsudenkishitsu-tō.
The Agency records a single-storey reinforced concrete building with a gabled sheet-metal roof, a building area of 203 square metres and a connecting corridor; it dates from 1927 and was extended in 1962; registration number 15-0384.
The Former Nakajima Water Purification Plant Standby Generator Room Building stands west of the pump room (Agency for Cultural Affairs). As the name says, it housed the plant’s standby generator, and it is the only one of the three registered buildings with a pitched roof.
A Plainer Face
The walls are finished in mortar, with a Parapet raised along the top and a row of dentils under the eaves (Agency for Cultural Affairs). Tall windows and small windows set between the pilasters give the plain walls their rhythm.
Where the pump room and the monitoring room have flat roofs, the Former Nakajima Water Purification Plant Standby Generator Room Building has a gabled roof clad in sheet metal. Its windows are kept within the bays between the pilasters, leaving the wall surfaces largely flat.
Why It Was Registered
The Agency for Cultural Affairs registered the Former Nakajima Water Purification Plant Standby Generator Room Building as a model of design. Its description notes that the exterior, more restrained than the pump room, adds variety to the plant buildings. Dentils and pilasters, both drawn from Western classical architecture, are used here with a light hand.
The Agency records an extension in 1962. The Waterworks Bureau chronology shows that improvements to the Nakajima plant under the third expansion project were also completed in March 1962, though no source links the two. The building was registered in 2013 with the pump room and the monitoring room.
What to Look For
Look for the fine row of dentils under the eaves and the alternation of tall and small windows between the pilasters (Agency for Cultural Affairs). On plain mortar walls, these small projections do a lot of work.
Set against the pump room next door to the east, the contrast is clear: built in the same year of 1927, the Former Nakajima Water Purification Plant Standby Generator Room Building has a pitched roof and much less ornament, and it lets the main building take the stage.
Visiting
The Former Nakajima Water Purification Plant Standby Generator Room Building is in Suido Park, west of the pump room, and its exterior can be seen from the park. It has a connecting corridor, so note how it sits in relation to the pump room. No official information was found on interior access or photography rules (checked November 2026).
Q&A
- When was the Former Nakajima Water Purification Plant Standby Generator Room Building built?
- In 1927, with an extension in 1962 (Agency for Cultural Affairs).
- How does the Former Nakajima Water Purification Plant generator room differ from the other buildings?
- It has a gabled sheet-metal roof instead of a flat roof, plain mortar walls and restrained ornament, with dentils under the eaves (Agency for Cultural Affairs).
- How big is the Former Nakajima Water Purification Plant generator room?
- It is a single-storey reinforced concrete building of 203 square metres with a connecting corridor (Agency for Cultural Affairs).
- Can you go inside the Former Nakajima Water Purification Plant generator room?
- No official information on interior access was found. The exterior can be seen from Suido Park.
- When was the Former Nakajima Water Purification Plant Standby Generator Room Building registered?
- On December 24, 2013 (Agency for Cultural Affairs).
Basic Information
| Name | Former Nakajima Water Purification Plant Standby Generator Room Building (旧中島浄水場予備発電機室棟) |
|---|---|
| Location | 3-247-2 Suidocho, Nagaoka City, Niigata Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2013/12/24 (Heisei 25) |
| Quantity | 1 building |
| Dimensions | Reinforced concrete, single storey, sheet-metal roof, building area 203 m², with connecting corridor |
| Owner | Nagaoka City |
| Public Access | Exterior visible from Suido Park; no official information on interior access |
References
- Former Nakajima Water Purification Plant Standby Generator Room Building (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00009747
- Nagaoka Waterworks, FY2022 edition (Nagaoka City Waterworks Bureau, Japanese)
- https://www.city.nagaoka.niigata.jp/suidou/doc/suidou/w-s_summary/summary-r04.pdf
- Suido Park (Niigata Prefecture Tourism Association, Japanese)
- https://niigata-kankou.or.jp/spot/detail_43801.html
Last verified: 2026.11.14
