U.S. Army Corps of Engineers, or USACE, is partnering with the Hawaii County Department of Public Works for a Waiakea and Palai streams flood reduction project.
The Waiakea-Palai project will include construction of detention basins, a diversion channel, levees and floodwalls to reduce flood risks to structures, property and critical infrastructure in the Waiakea Stream watershed and the Palai Stream watershed. The project will move into the design and implementation phase since there was no significant impact found in an environmental assessment and the project was approved by USACE Pacific Division on Sept. 29.
Design and implementation will begin after a project partner agreement is made between USACE and Hawaii County, which is anticipated by spring or summer 2023.
The proposed structures will temporarily store floodwaters and effectively route the water downstream, preventing overflow.
A severe flood that occurred on Nov. 2, 2000, caused significant damage to several residential areas including the Waiakea Stream area. Homes near Kawailani Street Bridge, Kupulau Road and several areas in Waiakea Uka were damaged due to flood waters exceeding stream capacities.
Another severe flood event occurred on Feb. 2, 2008, when the stream overflowed its banks, and 150 homes were damaged. A state of emergency was declared for Hilo, Puna and Ka‘u areas on Feb. 3, 2008, when 18 inches of rain fell in the Waiakea Uka area within 24 hours. For more information, contact the USACE Honolulu District Public Affairs Office at (808) 835-4003, or at cepoh-pa@usace.army.mil.