The design employs a 'side-overflow' system to ensure water allocation ratios remain constant even when river flow levels change.
It was built during a period of post-war reconstruction to eliminate water-sharing conflicts that had persisted for centuries.
The structure serves as a prime example of Taisho-era inspired civil engineering precision applied in the late 1940s.
It is officially designated as a Registered Tangible Cultural Property (Structure) by the Japanese Agency for Cultural Affairs.
The Higashiyama cylindrical water diversion tank is an industrial civil engineering structure constructed in 1948 to manage complex irrigation water distribution. It utilizes the principle of a proportional weir to precisely divide water from the Katakai River among three agricultural sectors. The tank features a 5-meter diameter reinforced concrete cylinder that allows water to overflow evenly regardless of input volume fluctuations. This design solved chronic water rights disputes among local farmers in the Toyama region. It remains an active irrigation facility integrated into the Uozu agricultural landscape. The site is recognized as a Registered Tangible Cultural Property of Japan.
From the pedestrian viewing platform that provides a direct, elevated perspective of the circular overflow pattern.
Combine this visit with a trip to the nearby Uozu Buried Forest Museum for a better understanding of the local geography.
The surrounding roads are narrow and primarily used for agricultural access; approach with caution.
The site is outdoors and unprotected from weather, so plan accordingly for sun or rain.
Do not attempt to walk on the walls or touch the water mechanism, as the site is functional infrastructure.
Respect the surrounding private farmland and do not obstruct agricultural vehicles or maintenance equipment.
