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EMCUTIVE SUMMARY Indian River County established its Beach and Restoration Committee to evaluate coastal erosion conditions throughout the County and to develop a strategy for protecting these valuable sandy beach areas. This study is an outcome of these efforts. It represents- a plan to manage the County's shoreline and to deal with coastal erosion on a planned basis. This report presents the Beach Preservation Plan as developed through consideration of coastal processes, historical trends, environmental considerations financial feasibility and needs. Summary of Coastal Processes and Beach Erosion The sands of Indian River County's shoreline are shaped and moved by the waves and ocean swells which which break upon it throughout the year. The wave climate is such as to generally move sand from north to south. Storms and persistent wind conditions can result in a wide range in the magnitude and direction of the sand movement. On an annual average however, sand is carried south at a net rate of•135,000 cubic yards per year. Various physical features along the County's coast affect the movement of this sand flow. Such changes are generally observed in the form of erosion or accretion of the shoreline. Three major features which have such impacts in Indian River County are: 1) Sebastian Inlet; 2) the offshore reef/ tock outcrop system; and 3) the large offshore shoal area. The effects of these features is reviewed in the following paragraphs. Sebastian Inlet The strong ebb and flood currents within Sebastian Inlet cause it have a major effect on the movement of sand in its vicinity. An annual average of 135,000 cubic yards of sand moves southward along Brevard County towards Sebastian Inlet. The inlet draws in the wave— suspended sands during flood tides. About 59,000 cubic yards per year are deposited in the quiescent waters on the Indian River Lagoon side of the inlet. Additional sands are carried offshore into deeper waters by the ebb currents. In either case, these sands are lost from the nearshore sand transport system. In total, the inlet is responsible for annual sand losses amounting to 83,700 cubic yards. It is only through recent efforts by the Sebastian Inlet District Commission, that some of the sands deposited in the inlet and lagoon have been dredged and deposited on beaches south of the inlet where they make up some of the losses due to the inlet. About 22,000 cubic yards per year have been bypassed around the inlet in this manner. Net losses are therefore reduced to 61,700 cubic yards per year as a result of these bypassing efforts. When sands are removed from the littoral transport system by a localized trap such as the inlet, the system adjusts to compensate for this change. The wave climate south of the inlet continues to provide the energy to move 135,000 cubic yards of sand southward per year. Since the Inlet prevents this quantity of sand from moving into the County, the sand in motion must come from a different 4.1 AUG 16 1988 moa 71 496