The interrelationship between inlet flow and delta morphology has an important effect upon the bypassing of sediment across inlets. Along the Sea Island Section of the Coastal Plain Physiographic Province the nature of inlet drainage and sediment bypassing profoundly influences patterns of beach erosion and accretion. Small coastal plain inlets generally have arcuate ebb deltas transected by a radially distributed pattern of channels. This arrangement permits an efficient flow of sediment across the inlet with little disturbance to the sediment budget of the adjacent shorelines. Several small inlets also have spits parallel to the shore that divert the flow of river water into the downdrift shore causing erosion. Accretion at the distal ends of these spits takes place at the expense of the proximal end of the spit where the shoreline erodes. Erosion eventually reopens a new channel across the proximal end of the spit and produces a second drainage reentrant. The major inlets along the coastal plain shoreline exhibit shoals with pronounced shore-normal orientations. The proximal ends of these spits may be attached or separated from the shore. When spits are attached to the shore, erosion is observed along the inlet margin and deposition is apparent at the distal end of the spit. When spits are separated from the shore, accretion is observed at shores adjacent to the inlet.

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