Lake Blalock is a reservoir in Spartanburg County, South Carolina, located on the Pacolet River about five miles north of Spartanburg. After its creation was authorized in 1976 by the Commissioners of Spartanburg Water System, Blalock Dam was constructed in 1983. The existing earthen dam is approximately 700ft. long and 70ft high. It was originally designed for a normal operating pool of 700ft, and the lake had approximately 35mi of shoreline. The existing spillway has a crest length of 270ft.To increase the safe yield of the reservoir, Spartanburg Water System raised the level of Lake Blalock by 10ft, increasing the water surface elevation to 710ft in 2004. This project was completed in 2006 and involved overlaying the existing earthen dam with a layer of roller compacted concrete, approximately 3ft in thickness, and constructing a new RCC stilling basin. The existing spillway was also upgraded by furnishing and installing three hydraulically operated spillway crest gates, constructing a new cast-in-place concrete ogee crest, and constructing a bridge across the spillway. In addition, the project also cleared approximately 300 acres around the perimeter of the reservoir.
