Former Nakajima Water Purification Plant

Former Nakajima Water Purification Plant

The Former Nakajima Water Purification Plant (旧中島浄水場, Kyū Nakajima Jōsuijō) in Suidocho, Nagaoka City, Niigata Prefecture, is the site of the city’s first water purification plant; its pump room, monitoring room and standby generator room, all completed in 1927, were registered as Registered Tangible Cultural Properties (structures) on December 24, 2013 (Agency for Cultural Affairs). All three belong to Nagaoka City.

According to the chronology of the Nagaoka City Waterworks Bureau, construction of the city’s waterworks began in January 1924, and partial supply started on August 1, 1926. The water came from the underflow of the Shinano River, the system was planned for 45,000 people, and the chronology counts it as the 81st waterworks in Japan. The project was completed in March 1927 with the Nakajima plant and its distribution tower, at a cost of 1,548,000 yen.

The plant was improved several times after the war. The Myoken Water Purification Plant was completed in 1971, and in November 1993 the Nakajima plant stopped operating so that it could be merged into the Myoken facilities (Niigata Prefecture Nagaoka Regional Office). The Waterworks Bureau puts its working life at 68 years. Rather than being demolished, the site was kept: the tower became known by the nickname “Water Tank” and the grounds became Suido Park. The plant has also been selected as one of Japan’s 100 Modern Waterworks (Nagaoka City Waterworks Bureau).

Three Buildings and the Water Tank

At the heart of the Former Nakajima Water Purification Plant is the L-shaped pump room, whose front wing held the high-lift pumps. The small monitoring room stands to its south-west and the standby generator room to its west (Agency for Cultural Affairs). All three are single-storey reinforced concrete buildings that share stone-faced bases and parapets, yet each has its own character: the pump room is dressed with giant pilasters and Art Deco details, the monitoring room repeats an arched parapet on all four sides, and the generator room keeps a pitched roof and little ornament. Each building has its own page.

South of the three buildings rises the water tower known as the Water Tank. The Agency for Cultural Affairs describes a cylindrical six-storey reinforced concrete shaft ringed with Tuscan pilasters, carrying a steel tank in a steel frame, 41.5 metres high in all; its design is attributed to Kanai Hikosaburo. The Water Tank was registered separately on September 2, 1998, and differs from the three buildings in both date of registration and lot number.

The Echigo Nagaoka Hundred Views, compiled by the Niigata Prefecture Nagaoka Regional Office, include a resident’s memory of the day after the Nagaoka air raid of August 1, 1945, when the Nakajima Water Tank could be seen across the burned-out Ote-dori. The Former Nakajima Water Purification Plant was a landmark that came through the war.

Visiting

The three buildings of the Former Nakajima Water Purification Plant and the Water Tank stand in Suido Park, Nagaoka. According to the Niigata Prefecture Tourism Association, the park is about 15 minutes on foot or about 5 minutes by car from JR Nagaoka Station, has parking for 30 cars and is free to enter. The park address is given as 3-11-1 Suidocho.

No official information was found on interior access to the buildings or on photography rules (checked November 2026). The exteriors can be seen from the park. Enquiries about the park go to the Nagaoka City urban facilities section.