The characteristics, management and costs of 213 diked impoundments in an important waterfowl wintering area in coastal South Carolina were studied in 1972-73 by intensive field surveys and interviews with owners, managers, construction companies, and tax collectors. Managed impoundments composed 22,536 acres of the total 98,451 acres of marshland and were claimed by 52 individuals or private groups and two state agencies. The objectives in management varied, but attracting waterfowl or snipe was an objective for 77 percent of the impoundments composing 87 percent (19,617 acres) of the total acreage of managed wetlands. Waterfowl food production was achieved primarily by manipulating natural vegetation through control of water Ievels and salinities, often in coordination with cattle grazing. Specific techniques of vegetation control are described, and dimensions and descriptions of dikes and water control structures are given. Harvest was estimated to be 11,438 ducks for the 1972-73 season, averaging 3.3 ducks per man-day and 0.6 ducks per acre of impoundment managed for waterfowl Total capital value of dikes and water control structures was estimated at $2,048,774. Capital investments annualized at 8 percent for 20 years and management costs directly attributable to the maintenance and management of impoundments amounted to $27.06 per acre per year or $530,836 for all impoundments in the study area managed for wildlife. Costs of hunting were estimated to be $150 per man-day and $45 per duck harvested.