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 study is in the initial planning phases and builds upon past technical studies conducted by USACE concerning flood risk at the Waimea River. 

The Waimea River Flood Control Project is located on the southwest coast of Kaua’i and it was authorized in May 1983 under Section 205 of the Flood Control Act of 1948. The project was completed in December 1984 at a cost of $3,272,000 (Federal: $3,212,400; non-Federal $60,000). The original levee was constructed by the County of Kaua’i in 1951.

The project was Federally modified and consists of 3,320 linear feet of cement-rubble-masonry floodwalls, 1,030 linear feet of levee toward the mouth of the river, 4,600 feet of rock protection along the levee toe, a 500-foot road section at the upstream end of the project, and floodgates. The project was funded in the fiscal year 1983 Jobs Bill.

This project provides flood damage reduction to the Waimea community from periodic flooding of the Waimea River. Approximately 614 homes and commercial buildings are currently protected by the project. The local sponsor is the County of Kaua’i, Department of Public Works.