Water budgets of two forested watersheds in South Carolina
Wetland protection, restoration and management require detail information of the water budgets for a particular system. Relatively undisturbed systems with long-term hydrologic records are extremely valuable for developing reference wetlands and detecting effects of management. Two forested flatwoods watersheds in the lower coastal plain of South Carolina have been monitored by the USDA Forest Service since 1976 with a primary objective to study the effects of forest management (prescribed burning) on water quality. This study synthesized the accumulated hydrologic data including streamflow and shallow groundwater table with a goal to develop long-term monthly and annual water budgets for the two watersheds. Measured hydro-metrological data and a monthly time step computer simulation model, MRSWARM, were used for analysis. This study found that long-term annual evapotranspiration for undisturbed mature forests was about 913 mm or 75% of annual precipitation. On a hydrology-averaged day, about 25% of the forested wetland watersheds was in aerobic condition and over 50% had a water table within 40 cm from land surface.