Gray's Beach Restoration Project

Customer: Kyo-ya Hotels & Resorts, LP

Start Year: 2007

City/Town: Waikiki, Hawaii, United States

Sea Engineering has been retained by Kyo-ya Hotels & Resorts, the owners of the Sheraton Waikiki Hotel in the middle of Waikiki Beach, to restore a beach fronting the hotel. The project name, Gray’s Beach, refers to a popular beach at this location in the 1920s. Over the years the beach disappeared, and the present shoreline fronting the hotel is a vertical concrete seawall. The primary project objectives are to restore the beach for the enjoyment of Hawaii residents and visitors, and to improve lateral access along the shore. The proposed restoration plan consists of constructing three rock T-head groins spaced 250 feet apart to stabilize the beach, and the placement of sand fill to create a dry beach area about 75 feet wide and 500 feet long. The groin stems would be about 160 feet long, with 100-foot wide heads (50 feet to either side of the stem), with the groin heads oriented to result in the gap between heads being parallel to the average approaching wave crest. The groin crest elevation would be +4 feet, and the beach crest would be about +5.5 feet, thus about half of the groin stems would be covered by sand. The sand fill would be obtained by the recovery of 15,000 cubic yards of sand from a deposit located about 4,000 feet offshore. Sea Engineering is the project manager, responsible for all design aspects as well as the environmental review process and the obtaining of all necessary Federal and State permits. The EIS process includes both a State EIS and a Federal NEPA EIS. The extensive permitting process includes Department of the Army permits for work in and filling of waters of the United States, and a State Conservation District Use Permit and Section 401 Water Quality Certification.