Hirase Water Source Former Office (Suikoan)

A 1935 Office With a Double-Arched Porch

The Hirase Water Source Former Office (Suikoan) (平瀬水源旧事務所（水交庵）) is a single-storey timber office built in 1935 inside the Hirase Water Purification Plant in Hirasecho, Kofu, Yamanashi Prefecture, and was entered on the national register of Registered Tangible Cultural Properties on December 12, 1997. Today it houses Suikōan, a small museum of Kofu's water supply.

The building is a one-storey timber structure under a tiled roof, with a building area of 242 square metres. Its signature is the entrance porch at the centre of the front, framed by two arches side by side. It was built as the plant's office a little over two decades after the water supply opened.

After the Second World War it became the residence of an officer of the U.S. military government stationed in Kofu. According to the waterworks bureau, a landscape that the Yamanashi-born painter Kuwabara Fukuho was commissioned to paint at that time still survives in the building as a mural.

Suikoan opened as a museum in 1988, marking the completion of the Arakawa Dam and the plant's expansion as well as the 75th anniversary of Kofu's waterworks. Kofu City explains the name as a wish that people would come to know and feel close to water, a place where people and water meet.

Why It Was Registered

The office was registered for its contribution to the historic landscape. The Agency for Cultural Affairs highlights the design of the double-arched porch and notes that local people know the building as a symbol of modernising civic life.

The other five Hirase properties are engineering works and a well house from the original construction of 1913. The Hirase Water Source Former Office (Suikoan) is the only one from the Showa period, and it speaks to the years when the utility had settled into routine operation and needed a proper administrative base.

Its sequence of uses adds to its value: plant office, officer's quarters under the Occupation, then museum. The mural keeps a record of that middle chapter on the building's own walls.

The Porch and the Displays Inside

Start with the porch. The building is otherwise a sober timber office under a tiled roof, and the pair of arches at the centre supplies the one Western accent that gives it a face.

According to Kofu City, stepping through the door sets off a recording of the song performed at the opening ceremony of Kofu's waterworks in 1912. Displays cover the city's water history, from wooden conduits of the Edo-period Kōfu Jōsui system to the water sellers of the Meiji era, and explain how the supply works.

The Hirase Water Source Former Office (Suikoan) stands near the plant's main gate, and the bureau's tour map marks its position, making it an easy landmark within the grounds.

Visiting

The Hirase Water Source Former Office (Suikoan) is inside the working Hirase plant and cannot be visited freely. The only way in is a group tour arranged through the Kofu City Waterworks and Sewerage Bureau.

Sources disagree about the interior. Kofu City's page on Suikoan, last updated in August 2022, says the museum can be seen on the plant tour, but a bureau notice to tour visitors dated June 2023 states that the Suikōan museum, along with the main administration building, cannot be visited. Going by the newer notice, the interior is probably closed for now, so check the current arrangements when booking.

Photography is not covered in the published guidance; ask about it at the same time.