mercury, stormwater runoff, turbidity, fecal coliform, sediment

Water quality Issues Surrounding The Santee River Basin

Drought

Along with global climate change and increasing population, the effects of the drought and water scarcity become a larger threat to the delicate ecologies within the Santee River basin.  Water quality modelers are often interested in the "7Q10" stream flow as a representative dry condition to use in modeling, particularly in cases where water quality is worst during low flow periods (e.g. if it is dominated by point sources such as wastewater treatment plants.) The 7Q10 stream flow is the yearly 7-day average low stream flow with a 10-year return period.  The past and recent drought in the southeast has exacerbated 7Q10 flow measurements increasing the occurrence of impaired water bodies and affected aquatic species.

Furthermore, a publically owned electric company by the name of Santee Cooper is obligated to make certain discharges from the lakes. The U.S. Army Corps of Engineers' contract requires a minimum discharge of water from the Jefferies Hydroelectric Station into the Tailrace Canal, where it flows into the Cooper River and Charleston Harbor. The flow of freshwater prevents saltwater intrusion that could impact industries along the river. Additionally, the utility's Federal Energy Regulatory Commission license requires a minimum discharge of water from Santee Cooper's Spillway unit into the Santee River. With current inflows, required discharges and natural evaporation, which is worsened because of drought and evaporation, the lake elevations, are dropping one to two inches a day.  The highly variant water levels confuse fish in that the bedding areas that they know become unavailable during low water levels.