THE POTENTIOMETRIC SURFACES OF THE BLACK CREEK, MIDDENDORF, AND FLORIDAN AQUIFERS OF SOUTH CAROLINA: RECENT FINDINGS AND A BRIEF HISTORICAL PERSPECTIVE

The potentiometric surfaces of the Floridan aquifer and its updip clastic equivalent, the Tertiary sand aquifer; the Middendorf and the Black Creek aquifers were measured in 2010, 2011 and 2012, respectively, by South Carolina Department of Natural Resources staff and others from a network of more than 300 wells. Synoptic measurements of the potentiometric surface of each aquifer in the South Carolina Coastal Plain have been taken at roughly 5-year intervals for nearly 30 years. The recent potentiometric maps of these aquifers are compared to previous maps, with hydrographs of selected wells noting trends.

The Floridan, Black Creek and Middendorf aquifers are the source of water for many public, industrial, and agricultural supplies in the Coastal Plain of South Carolina. These important water resources are monitored by regularly measuring the nonpumping water levels in wells. The potentiometric surface of an aquifer is defined by the elevations at which water stands in tightly cased wells completed in the aquifer.

The potentiometric surface of the Floridan aquifer and its updip clastic equivalent, the Tertiary sand aquifer, for late October, November, and early December 2010 shows a generally southeastward groundwater flow affected by several potentiometric depressions. These cones of depression have developed because of groundwater pumping in Colleton and Dorchester Counties. Water levels in Jasper and Beaufort Counties continue to be affected by pumping in the Savannah, Ga. area.

The potentiometric surface of the Middendorf aquifer for November 2011 shows that the generally southeastward groundwater flow is affected by several potentiometric lows. These cones of depression have developed because of groundwater pumping in Florence and Williamsburg Counties and Berkeley and Charleston Counties.

The potentiometric surface of the Black Creek aquifer for November 2012 shows that the generally southeastward groundwater flow is affected by several potentiometric lows. These cones of depression have developed because of groundwater pumping in Georgetown, Florence, and Williamsburg Counties.