Beppu City Asami Water Purification Plant

What Is the Beppu City Asami Water Purification Plant?

The Beppu City Asami Water Purification Plant (別府市朝見浄水場, Asami Jōsuijō) is a municipal water treatment works in Asami 2-chome, Beppu City, Oita Prefecture, completed in March 1917, and five of its structures were registered as Registered Tangible Cultural Properties on September 3, 1997. Locals simply call it the Asami Jōsuijō, and the city lists the facility under that name.

The five registrations cover the distribution reservoir, the reservoir's north and south entrances, the collecting well house and the water meter house, numbered consecutively from 44-0012 to 44-0016. All five were registered as a Registered Tangible Cultural Property under the same criterion: structures that contribute to the historic landscape of the country. Four of them stand together inside the hilltop plant. The water meter house sits on its own, down on lower ground to the north.

According to the Beppu Water and Sewerage Bureau, Beppu's modern waterworks was the first in Oita Prefecture and only the 33rd in Japan to begin supplying water. The registered structures preserve that early system inside a plant that is still running.

Oita Prefecture's First Modern Waterworks

The town of Beppu began planning a water supply in 1906. Negotiations over national subsidies dragged on, and approval for the project came only in July 1913. A groundbreaking ceremony was held on the Asami site on July 26, 1914.

Recession and late deliveries of materials pushed the schedule back twice. The works were completed in March 1917 and water began flowing in April. The supply came from two streams, the Otobaru River and the Ayugaeri River, in a 60:40 ratio. At the Asami plant the water passed through three slow sand filters and two distribution reservoirs, then ran downhill to the town by gravity alone, with no pumps. The system was designed for 25,000 people and a peak of 2,800 cubic meters a day.

Beppu became a city in 1924, and demand soon outran supply. The city launched its First Expansion Project, approved in July 1925, begun on February 6, 1926 and completed in November 1927. The slow sand filters went from three to seven, the distribution reservoirs from two to four, and a second collecting well house, a metering basin and a water meter house were added. The design population rose to 75,000.

Expansion continued for decades. City records give the present Asami plant, as of April 2017, as a rapid filtration facility built in 1969 with a capacity of 58,000 cubic meters a day.

Two Records of When They Were Built

The dates for the five registered structures at the Beppu City Asami Water Purification Plant depend on which source you read. The Agency for Cultural Affairs database dates the distribution reservoir and the collecting well house to 1917, the two entrances to 1926, and the water meter house to 1927. Its note on the reservoir says it could supply 25,000 people when finished, treating it as part of the original works.

The city's own centennial history, published by the Water and Sewerage Bureau in 2017, tells a different story. It describes the registered reservoir, both entrances, the second collecting well house and the water meter house as products of the First Expansion Project. At one of its summer open days the bureau also explained that the collecting well house was built during that expansion, beside the original first well house of 1917 (now gone), and designed to resemble it.

The individual pages follow the Agency for Cultural Affairs for dates and basic data, and set out the city's account alongside. For the two entrances and the water meter house, the two sources largely agree.

How the Five Structures Are Laid Out

The Asami plant sits on high ground about 1 kilometer southwest of JR Beppu Station. The Agency for Cultural Affairs places the distribution reservoir at the western edge of the site, with a maintenance entrance on each of its north and south sides. Both entrances are free-standing reinforced concrete huts of just 13 square meters.

The collecting well house stands within the same grounds. Octagonal in plan and capped with a rounded roof, it is the most eye-catching of the five.

The water meter house is the outlier, set on low ground a short way north of the plant. Put the hilltop reservoir and the low-lying meter house side by side on a map and you can see how much this gravity-fed system relied on the lie of the land.

Every one of the five is a working structure, yet each wears Western-style detail: a pediment, ornamented capitals, arched window frames, joints scored to look like cut stone. The Agency's descriptions keep returning to the same point, that even these small utility buildings were treated as serious architecture.

Visiting: Access and Open Days

The Beppu City Asami Water Purification Plant still supplies the city's water. Its address is 2-24-5 Asami, Beppu. The city website gives no standing arrangement for public visits, so close-up views of the four structures inside the grounds depend on events such as the summer open days run by the Water and Sewerage Bureau. In 2026 the bureau held a joint tour of the Beppu Power Station and the Asami plant with Oita Prefecture's Enterprise Bureau on August 1, aimed mainly at local elementary and junior high school students and their parents, with 60 places allocated by lottery and no charge.

City notices say nothing about photography, so follow the staff's instructions on any tour. For questions about access or what can be seen from outside, contact the Asami plant (tel. 0977-22-0527) or the Beppu Water and Sewerage Bureau.

The plant is about a 15-minute walk from JR Beppu Station. By car it is about 5 minutes (about 1 kilometer) from the station, and about 10 minutes (about 3.5 kilometers) from either the Beppu Interchange or Beppu International Tourist Port. By bus, take route 19 (Uchinari Line) from the east exit of JR Beppu Station and get off at Kamihata. The city's facility page lists parking on site, though open-day notices warn that spaces are limited and ask visitors to share cars.