Lake Hickory, North Carolina: Analysis of ambient conditions and simulation of hydrodynamics, constituent transport, and water-quality characteristics, 1993-94

Abstract

Similar water-quality problems were observed in other urban-industrial areas of the Catawba River Basin during the late 1950's before many technological advances in wastewater treatment and water-quality protection measures were implemented (North Carolina Department of Water Resources, 1961). Wilder and Slack (197la, b) reported that concentrations of nitrate and chloride in Middle Little River and Drowning Creek were similar to natural levels, but concentrations of nitrate in Gunpowder Creek were slightly elevated. The North Carolina Department of Environment, Health, and Natural Resources (1994a, b) reported that Upper Little River and Middle Little River fully supported their designated uses and received "Good" water-quality ratings based on analysis of benthic macroinvertebrates. A "Poor" rating was given to a small tributary receiving toxic effluent from a textile finishing plant. This tributary drains into the mainstem of Lake Hickory upstream from the U.S. Highway 321 bridge.Water-quality investigations of unpolluted streams near Lake Hickory are valuable for comparative purposes. From 1973 through 1978, the USGS, in cooperation with the North Carolina Department of Natural Resources and Community Development, investigated 39 streams with 90 to 100 percent forested basins. Results were used to characterize water-quality conditions in relatively undisturbed watersheds and to delineate five geochemical zones within North Carolina (Simmons and Heath, 1982). Although none of the sites were in the Lake Hickory drainage area, 16 were located in the same geochemical zone (zone I). As might be expected, the pristine streams contained low concentrations of major inorganic constituents, nitrogen and phosphorus, and trace elements (Simmons and Heath, 1982). A supplemental investigation at nine of the original sites, including three sites in zone I, was conducted from 1985 through 1988(Caldwell, 1992.Previous investigations of Lake Hickory primarily focused on classifying the trophic status of the reservoir. Since the early 1970's, investigators have described Lake Hickory as eutrophic (U.S.