Spatial Distribution of Sediments Within the Charleston Harbor Estuary Following Drainage Modification

Abstract

The Charleston Harbor estuary in South Carolina experienced major changes in hydrographic conditions in 1985 as a result of discharge modification in the Cooper River. Monthly mean flow was reduced from 418 to 122 m³/ sec. In 1988, the spatial distribution of surficial sediments was surveyed by sampling 178 sites throughout the lower portion of the estuary. Results from this survey provided a basis for comparisons with data collected from a similar study conducted prior to rediversion in 1972. Sediment distribution patterns observed throughout most of the study area during 1988 were generally similar to those observed during 1972, with the exception of localized changes along the east bank of the Cooper River, the lower Ashley River and the upper harbor basin. These differences were not attributed to rediversion, since similar differences were also noted in other studies conducted prior to the major alteration in water flow through the Cooper River