Maryland Department of Natural Resources


Potentiometric surface and water-level difference maps of selected confined aquifers in Southern Maryland and Maryland’s Eastern Shore, 1975-2013

2014, Staley, A.W., Andreasen, D.C., and Curtin, S.E.

Open File Report 14-02-02

Key Results

Groundwater is the principal source of freshwater supply in most of Southern Maryland and Maryland’s Eastern Shore. It is also the source of freshwater supply used in the operation of the Calvert Cliffs, Chalk Point, and Morgantown power plants. Increased groundwater withdrawals over the last several decades have caused groundwater levels to decline. This report presents potentiometric-surface maps of the Aquia and Magothy aquifers and the Upper Patapsco, Lower Patapsco, and Patuxent aquifer systems using water levels measured during September 2013. Water-level difference maps are also presented for four of these aquifers. The water-level differences in the Aquia aquifer are shown using groundwater-level data from 1982 and 2013, while the water-level differences are presented for the Magothy aquifer using data from 1975 and 2013. Water-level difference maps for both the Upper Patapsco and Lower Patapsco aquifer systems are presented using data from 1990 and 2013.

The potentiometric surface maps show water levels ranging from 165 feet above sea level to 199 feet below sea level. Water levels have declined by as much as 113 feet in the Aquia aquifer since 1982, 81 feet in the Magothy aquifer since 1975, and 61 and 95 feet in the Upper Patapsco and Lower Patapsco aquifer systems, respectively, since 1990.