Sedimentation in Crowders Creek cove in Lake Wylie, located in York County, South Carolina, has restricted boat navigation and made a boat ramp unusable. To provide baseline information, the U.S. Geological Survey, in cooperation with the York County Council, collected bathymetric and bed-sediment data in the cove, and streamflow and suspended-sediment data in a free-flowing reach of Crowders Creek. Bathymetric data from a survey of the cove made in November 1999 were compared with bathymetric data derived from a 1973 U.S. Geological Survey topographic map. It was determined that at water-surface elevation of 568 feet, the volume of the cove available for water storage had decreased 90 percent, from 1.3 million cubic yards in 1973 to 135,000 cubic yards in 1999. Continuous water-level and streamflow data were collected at a U.S. Geological Survey stream-gaging station on Crowders Creek near Clover, South Carolina, for the period October 1, 1999, to April 30, 2000. Suspended-sediment concentration data were collected at four sites on February 14, 2000. The maximum instantaneous streamflow recorded during this event was 864 cubic feet per second, and the largest suspended-sediment load was calculated to be 2,120 tons per day. Bed-sediment samples were collected at four locations in the study area: one in the lower reach of Crowders Creek and three in the cove. These samples were analyzed for a total of 44 trace elements, 29 organochlorine pesticides, degradation products and polychlorinated biphenyls, and for particle-size distribution. None of the trace element concentrations exceeded guidelines for the concentrations above which adverse effects on stream biota are expected to occur. Two of 29 organochlorine pesticides were detected.p,p'-DDT at 11 micrograms per kilogram was detected at one site, and p,p'-DDE at 3.2 micrograms per kilogram was detected at another site. Particle-size analyses at these four sampling sites indicated that at least 60 percent of the sediments are smaller than 0.063 millimeter, which indicates the sediment is composed mostly of silts and clays.
Additional publication details
USGS Numbered Series
Assessment of sedimentation in Crowders Creek, York County, South Carolina, 1999-2000
U.S. Dept. of the Interior, U.S. Geological Survey ;
Information Services [distributor],