LIMNOLOGICAL EVOLUTION OF LAKE SHEPHERD SPRINGS, CRAWFORD COUNTY, NW ARKANSAS

Lake Shepherd Springs is a man-made lake located in Crawford County, Arkansas approximately 45 km northeast of the city of Fort Smith. The lake occupies an area of about 543 acres within a watershed consisting of 90% forest cover. It has a maximum depth of 23 m and an average depth of 9 m. The lake is maintained and monitored by the Utilities Department of the city of Fort Smith for domestic water provision, flood control and for limited recreation (fishing). Since its impoundment in 1956 a variety of water quality parameters including temperature, dissolved oxygen, total dissolved solids, turbidity, nutrients, trace metals, etc have been monitored. This study compiles and presents the archived water quality data as well as data from previous studies in a Geographical Information System (GIS), as a means of documenting the limnological evolution of this lake, and consequently its present environmental state. The development of a GIS water quality database and related maps depicting the variations of parameters is useful for developing empirical, predictive models of the evolution of water quality in this lake. The historical trends captured in this work provide an understanding of the controlling conditions, processes and interrelationships between Lake Shepherd Springs, its watershed and the surrounding areas. These data will, in addition, provide knowledge on the lake’s productivity changes and potential sources of pollutants, taking into account the complexity of the watershed structure (land-use, geology, and topography). This work will provide a baseline for long-term study and enhanced management practices in Lake Shepherd Springs.