Conduit Gate of Tase Dam

The Tase Dam in Iwate Prefecture, completed in 1954 and currently managed by the Ministry of Land, Infrastructure, Transport and Tourism, is the first multi-purpose dam in Japan. It is characterized by its water discharge system (the discharge volume per gate is 120 m3/s) from near the bottom of the lake that uses high-pressure slide gates (conduit gates) and tubes. During the design process, the engineers learned from American manufacturers how to operate and install the system. However, regarding the discharge tubes, experiments and theory development, starting from the basics, were conducted in Japan, and the design applicable to dams in Japan was established.
In this manner, the Tase Dam mechanical system of high-pressure discharge tubes became indispensable to the spread of multi-purpose dams in Japan, greatly benefiting the Japanese people.