Former Sogi Power Station

A Meiji Hydroelectric Station beneath a Reservoir

The Former Sogi Power Station (旧曽木発電所, Kyu Sogi Hatsudensho) is the ruin of a hydroelectric station built in 1909 at Oguchi, Isa City, Kagoshima Prefecture, whose main building and head tank were registered in 2006 as two Registered Tangible Cultural Properties.

They belong to the national government (Ministry of Land, Infrastructure, Transport and Tourism). The Agency for Cultural Affairs calls the main building one of the earliest large brick buildings in southern Kyushu, and the head tank a remnant of an early canal-type power station in Kyushu.

The Tsuruda Dam Management Office explains that the station generated power from the drop of the Sogi Falls.

Submerged and Preserved

According to the dam office, when the Tsuruda Dam was completed in 1966 the station sank beneath Lake Otsuru and gradually faded from memory.

A preservation movement began in 1999, led by the former Oguchi City (now Isa) with the prefecture, the state and non-profit groups. In 2004 the dam office began reinforcement: removing silt, adding steel supports and repairing walls and brickwork. With about 1,600 brick supporters writing their names on replacement bricks, the work was completed in 2010.

The office notes that the station was recognised as a heritage of industrial modernisation in 2007 and reached its centenary in 2009.

Layout of the Remains

The Agency describes the main building as a generator hall with an office wing at right angles. The head tank stands on high ground to the northeast, regulating the flow of water for generation, with four openings in its face for the penstocks.

Together the two remains show the canal-type system: water dropped from the head tank through penstocks to generate power in the building below.

Visiting the Former Sogi Power Station

Isa City says the remains can be viewed all year, but the brick buildings emerge in the dry season from May to September. They are normally viewed from the observation park on the opposite bank, which has parking. How much is visible depends on the reservoir level, and the dam office publishes the relationship between water level and the ruins.

Isa City reports that heavy rain on 10 July 2021 caused part of the ruins, the machine room, to collapse; repairs are under way with no completion date set. The dam office gives about 30 minutes by car from the Tsuruda Dam via Route 267 or Prefectural Road 404. Enquiries: Isa City tourism PR section, 0995-29-4113.