In June 2024, the U.S. Army Corps of Engineers, Honolulu District initiated the Waimea River Flood Control Project Modification Feasibility Study at the request of and in partnership with the County of Kaua‘i, as represented by the Department of Public Works pursuant to Section 216 of the Flood Control Act of 1970 (Public Law 91-611).

The study received in FY24 $500,000 federal funds under the Consolidated Appropriations Act of 2024 (PL 118-42) and $1.5 million non-federal funds.

Section 216 authorizes and funds USACE to initiate review of the operation of completed Corps projects and investigate recommendations for modification of the structures or their operation, and for improving the quality of the environment in the overall public interest.

USACE and the County of Kaua‘i will develop and evaluate structural, non-structural and natural-nature based features and measures that may involve modifying the existing Waimea Flood Control Project necessary to manage flood risk to Waimea residents. The original levee project was constructed by the County of Kaua‘i in 1951 and later modified by USACE in 1984, pursuant to Section 205 of the Flood Control Act of 1948, as amended. The project team is currently conducting engineering, economic, and environmental analysis to support identification of the tentatively selected flood risk management solution. The project team is currently conducting engineering, economic, and environmental analysis to support identification of the tentatively selected flood risk management solution.

The Waimea River Flood Control Project (FCP) is located on the southwest coast of the island of Kauai. The project was authorized in May 1983 under Section 205 of the Flood Control Act of 1948, as amended. The local sponsor is the County of Kauai (County).

The project was constructed by the County in 1951.  It was later modified by the U.S. Army Corps of Engineers (Corps) in 1984, with the Corps and County cost sharing.  The project consists of 3,320 feet of cement-rubble-masonry floodwalls, 1,030 feet of levee toward the mouth of the river, 4,600 feet of rock protection along levee toe, 500 feet road rising section at the upstream end of the project and floodgates. 

This Waimea River FCP reduces flood risk for approximately 614 commercial buildings and homes from the periodic flooding of the Waimea River. 

The project was turned over to the local sponsor upon construction completion to operate and maintain.  The Corps conducts annual inspections with the local sponsor to ensure the project is performing as intended.