Lake Tateshina’s Circular Tank Diversion Works


Lake Tateshina’s Circular Tank Diversion Works村

Due to the low water temperature in the Kosai River, the main water source for the Takinoyu Weir, Lake Tateshina was constructed as a reservoir to warm the water.
Since the location of the reservoir was the water source for the Kubota Weir, there was a need to divide water between the Takinoyu Weir and the Kubota Weir in a 9:1 ratio in keeping with an arrangement from the Edo Period, so a “circular tank diversion works” was constructed. The water spilling from the cylindrical tank is accurately divided by the ratio of the circle’s circumference, and this decreased fighting over water.


address Kitayama, Chino City
since 1952
access (1) About 30 minutes by car from Suwa IC
(2) About 30 minutes by bus from Chino Station on the JR Chuo Main Line


Agricultural Land Development Division, Agricultural Administration Department, Nagano Prefecture