Comprehensive Condition Survey and Storm Waves, Circulation, and Sediment Study, Dana Point Harbor, California

Abstract : The U.S. Army Engineer District, Los Angeles and the Coastal Inlets Research Program have conducted a comprehensive study to investigate wave, flow, sediment transport, and permeable breakwaters with rocky outcrop bottom at Dana Point Harbor, as a part of the harbor revitalization project, on the southern Orange County coast, CA. The 5,500-ft shore-parallel West Breakwater and 2,250-ft shorenormal East Breakwater to protect the harbor are the main interest in the study of the structural integrity and functionality. The field data collection includes 2009 survey of breakwaters, marinas, harbor entrance and surrounding at the harbor, and installation of a pair of ADCPs to measure water levels, waves, and currents inside and outside West Breakwater. The numerical models were used to calculate wave transmission, current and sediment seepage through permeable breakwaters and circulation in the harbor. Permeable breakwaters are simulated by models under wind forcing, tides, bottom friction, and wave reflection. The oceanographic design criteria established previously for the Harbor were updated based on historical storm waves and the present model simulations for 50-yr and 100-yr return periods. The data analysis and model results together provide information to ascertain the action to repair breakwaters and structural alternatives to improve the navigation channel maintenance and tidal flushing in the harbor.