THE PROLIFERATION OF STORMWATER PONDS IN COASTAL SOUTH CAROLINA, USA

Stormwater ponds are inland aquatic systems specifically constructed to meet stormwater permit requirements associated with land development. Although commonly associated with development practices nationally and internationally, stormwater ponds are especially prevalent in the southeastern coastal plain of the United States, an area that has very few natural ponds and lakes. Based on 2021 aerial imagery, the eight coastal counties of South Carolina, USA, contain a total of 27,651 ponds, which collectively comprise a cumulative area of 146.7 km². Of this total, 12,278 ponds were obviously associated with development, and thus interpreted as created for or functioning as stormwater best management practices. The remainder were associated with agricultural or rural land uses in the more inland region of the coastal zone. For the two largest coastal urban areas, a retrospective analysis revealed total stormwater pond area increased by more than 4 percent per year between 1994 and 2021, which is greater than the rate of increase in developed land cover and suggests pond density within developed landscapes is increasing over time. Concurrent field research efforts by our group have revealed these ponds to be hotspots of sediment carbon burial, phytoplankton production and nutrient cycling, and dissolved organic matter export. As such, the proliferation of ponds in coastal SC represents a significant alteration of coastal hydrology with attendant consequences for the transport and transformations of material carried by stormwater runoff to coastal receiving waters.

Presentation Preference: Oral

Primary Presenter: Erik Smith, University of South Carolina (erik@baruch.sc.edu)

Authors:

Erik Smith, University of South Carolina  (erik@baruch.sc.edu)

Denise Sanger, South Carolina Department of Natural Resources  (sangerd@dnr.sc.gov)

Andrew Tweel, South Carolina Department of Natural Resources  (tweela@dnr.sc.gov)