The total drainage area of Mountain Creek, Texas, is 304 sq mi. The stream-gaging stations on Mountain Creek near Cedar Hill and Walnut Creek near Mansfield provide hydrologic data to define runoff characteristics from small drainage basins. They also serve as index stations for inflow into the reservoir and provide operational data for the reservoir. In addition, the station Walnut Creek near Mansfield is equipped with a recording rain gage. The stage station near Duncanville provides data pertinent to operation of the gates in the Mountain Creek Lake Dam. The reservoir-content station at the dam provides records of reservoir state and contents. The stream-gaging station Mountain Creek at Grand Prairie provides records of outflow from Mountain Creek Lake and the basin. Basin outflow for the 1976 water year was 78,660 acre-feet which is only 1,140 acre-feet above the 16-year (1960-76) average of 77,520 acre-feet. Storage in Mountain Creek Lake showed a net gain of 760 acre-feet during the water year. Rainfall over the study area for the 1976 water year was about 32 inches, which is about 2 inches below the long-term mean rainfall (1960-75) for the area. (Woodard-USGS)
