Inlet Impacts on Local Coastal Processes

St. Augustine Inlet, a trained, ebb-dominated inlet, acts as an efficient sediment trap by impounding sediments in ebb and, to a lesser extent, flood shoals. The ebb shoal, containing 23 million cy of sand by 1994, impounds 425,000 cy/yr of sand without signs of abatement. Inlet sand trapping causes chronic erosion of the south beach. The large inlet sand trapping capacity appears to be related to the large magnitudes of and the large mismatch between the ebb and flood discharge prisms. Spreading characteristics of the ebb jet are consistent with observed sedimentation patterns of the ebb shoal.