Concurrent Session 01B: A Tale of Two Konas: Dam Safety Preparedness and Response During the March 2026 Flood Events at Oahu's North Shore

Two consecutive multi-day storm systems impacted the Hawaiian Islands during a 14-day period from 03/11/26 - 03/25/26, resulting in adverse flood conditions in several locations, including Wahiawa Dam on the Island of Oahu. The flood loading resulted in three distinct rapid-rises in reservoir levels that triggered two rounds of emergency notifications warning of a possible dam failure.

Tony Koyamatsu, P.E.

HI Department of Land & Natural Resources

Tony Koyamatsu, P.E.
Dam Safety Engineer
Hawaii Dept of Land & Natural Resources
Honolulu, Hawaii

Tony Koyamatsu is a registered professional engineer with six years of experience in dam safety. Tony works for the State of Hawaii Department of Land & Natural Resources in the Dam Safety Program. He oversees dams on the island of Oahu and the Big Island of Hawaii, as well as a small land maintenance crew. Tony’s work focuses on dam safety inspections, permit application reviews, enforcement, and emergency preparedness and response. In a previous life, Tony worked for a local electric utility.