New neighborhoods and commercial properties have ponds or underground storage systems to manage stormwater quantity and quality. A stormwater system's success depends upon proper implementation and operation of an annual maintenance plan. Properly functioning stormwater systems remove sediment and pollutants that may impact downstream properties and Waters of the State.

Maintenance Responsibilities

All ponds and underground storage systems are privately owned and maintained. Dorchester County does not perform maintenance, except in emergency situations. Concerns such as mosquitoes, dredging, algae control, fish kills, and trash removal must be addressed by the property owner or homeowner's association. Information on pond management can be obtained from Dorchester County, South Carolina Department of Natural Resources, or the Ashley River Education Consortium.

Flood Control

Ponds help prevent flooding of downstream properties by storing and gradually discharging stormwater runoff through drainage pipes. Stormwater discharge rates vary with the 2-year, 10-year, 25-year, and 50-year storm events. To function properly, drainage pipes must never be blocked with debris or other materials.

Water Quality

Storm water ponds trap sediment and other pollutants such as nitrogen and phosphorus from fertilizers, heavy metals from vehicles, and fecal coliform from pet waste. Routing this waste through a pond system minimizes pollutant discharge to creeks and marshes where it can damage the environment and its ecosystem.

As ponds fill up with sediment, they may become shallow. This lack of pond depth promotes vegetative growth, decreases pollutant removal efficiency, and increases downstream flooding risks. Approximately ten years after construction, ponds may require dredging to remove the sediment buildup. Owners must maintain funds for dredging ponds.

Reducing lawn fertilizer use deters algae and weed growth in the ponds. Collecting pet waste and disposing of it in trash receptacles prevents fecal coliform from entering the stormwater system and contaminating Waters of the State and other downstream waterbodies.

Annual Inspections

Ponds and post-construction stormwater management systems must be inspected at least twice a year, or more frequently as necessary, or as specified by a manufacturer. Inspection reports shall be generated and kept on file for a minimum of two (2) years. Reports must be made available to Dorchester County upon request. If generated by a third party, it shall remain the owner’s (or owners’) responsibility to maintain the reports.

Forms & Manuals

• Operating & Maintenance Agreement
• Pond Maintenance Agreement
• Example Pond Maintenance Plan
• Transfer of Ownership
• EPA’s Wet Pond and Wetland Management Guide

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