In 1940 a long, wide earthen dike was constructed around the sink basin to keep water in the lake. A concrete spillway was constructed for overflow with metal pipes of diameter and sluice gates built into the earthen dikes at the sink. Just before 1950 additional earthen dams were built across Cromartie Arm (to the south) and Strickland Arm (to the north) and bordering Horseshoe Plantation. The purpose of these dams was to keep water in Cromartie and Strickland Arms for the plantations.