Monitoring on Increased Seepage at Iwaya Dam
2019 Volume 29 Issue 1 Pages 17-27
Details
2019 Volume 29 Issue 1 Pages 17-27
Iwaya Dam managed by Japan Water Agency (JWA) is a rockfill dam of 127.5 meters high, 40 years after construction. In Iwaya dam, seepage increased with turbidity from November to December 2013, and the increase amounted to about 100 L/min in one month. In response to this, JWA upgraded the on-site monitoring system, investigated the cause, and established a panel of experts on dam safety. After that, it stabilized for more than 1 year ago. And the seepage decreased in 2016. On the other hand, cause of the increase in seepage is still unknown. JWA decided to continue regular safety management as aiming to the recurrence of the event. This paper shows the process from the increase to the current safety management.
