The Kahawainui Stream project is located in Laie on the island of Oahu and was completed in 1990 at a total cost of $5,246,115. The project was authorized under Section 205 of the Flood Control Act of 1948, as amended. The project consisted of 550 feet of concrete channel; 450 feet of excavated earth channel; 500 feet of concrete floodwalls; 1,420 feet of levees; and raising two roadways in elevation. Design discharge at the mouth of the stream was 17,800 cubic feet per second.
The project was designed to provide standard project flood level of protection. The project prevents an estimated $675,000 in damages annually under present development conditions along the Lā‘ie coastal plain. The project has prevented over $4.1 million in damages due to a storm that occurred in March 1991. The local sponsor is the City and County of Honolulu.