The Kaumalapau Deep Draft Harbor project is located on the southwest coast of the island of Lanai.  Project completion was in July 2007 at a cost of $28,200,000 (Federal: $22,560,000; non-Federal: $5,640,000).

The breakwater-crest length is 320 feet and the maximum height for the toe is 60 feet. The project repaired the existing breakwater built during the 1920s that was previously owned by private interests.

Repeated storm events in the 1980s and early 1990s caused significant damage to the existing breakwater. In July 2000, the Kaumalapau Harbor was officially transferred from Lanai Company to the State of Hawaii.