Nikō Basin Intake
In 1886, the Imperial Navy designated Kure as the future location of a major naval base. Operation of the base would require large quantities of water for supplying the ships and for use in shipbuilding, so the development of water supply facilities became a top priority. The Navy began construction of the Nikō Basin Intake in 1888, and it was finished a year later. Kure was the third city in the nation, after Yokohama and Hakodate, to build the infrastructure for a modern water supply system. Water from the Nikō river is treated at the Miyahara Water Purification Plant, then transported to the city of Kure through iron pipes that are pressurized to prevent contamination.
The Miyahara Water Purification Plant was completed and connected to the Nikō Basin Intake in 1890. It purified the water collected from the intake using a slow sand filter system. Kure Naval Base was expanded following the Russo-Japanese War (1904–1905), increasing the demand for water, and in 1918 the water supply system was expanded to meet this need. A large reservoir was created by damming an area between the villages of Honjō and Yakiyama, approximately 7 kilometers away. The reservoir is fed by the Nikō River, as well as three smaller tributaries. Honjō Dam was a piece of vital infrastructure that benefited not just the naval base but also the residents of Kure, who had previously been dependent on less reliable or less sanitary sources of water. The water diverted from Nikō River through the intake is still used for industrial purposes at the Kure shipyard. In this way, the Nikō Basin Intake exemplifies how the militarization of the country was a driving force behind its modernization. For these reasons, it was designated a Tangible Cultural Heritage by the national government in 1998.
The Nikō Basin Intake terminates in an impressive granite archway that straddles the waterway. The section just before the arch was created by boring a canal through the middle of a large rock to divert the Nikō River. This feat of engineering and stonework has stood for over 120 years without failing or breaking down, and it is a testament to the advanced skills and technology that were implemented in building the intake.
The intake is located in Nikō Gorge, which was carved out by the Nikō River, creating two waterfalls (Odaki and Medaki). In 1965, the municipal government designated the landscape surrounding the intake a Place of Scenic Beauty.
