Georgia Water Science Center
Home | Ground-Water Quality | Surface-Water Flow and Quality | How Can I Get the Data?
Ground-water-level fluctuations measured in wells are caused by changes in aquifer storage. When recharge to an aquifer exceeds discharge, ground-water levels rise; and when discharge exceeds recharge, ground-water levels decline. Recharge varies in response to precipitation and surface-water infiltration into an aquifer. Discharge occurs as natural flow from an aquifer to streams and springs, as evapotranspiration, and as withdrawal from wells. Water levels in aquifers in Georgia typically follow a cyclic pattern of seasonal fluctuation, with rising water levels during winter and spring due to greater recharge from precipitation, and declining water levels during summer and fall due to less recharge, greater evapotranspiration, and pumping.
Ground-water pumping is the most significant human activity that affects the amount of ground water in storage and the rate of discharge from an aquifer. As ground-water storage is depleted within the radius of influence of pumping, water levels in the aquifer decline, forming a cone of depression around the well. In areas having a high density of pumped wells, multiple cones of depression can form and produce water-level declines across a large area. These declines may alter ground-water-flow directions, reduce flow to streams, capture water from a stream or adjacent aquifer, or alter ground-water quality. Ground-water-level fluctuations measured in wells are caused by changes in aquifer storage. When recharge to an aquifer exceeds discharge, ground-water levels rise; and when discharge exceeds recharge, ground-water, ground-water levels fall.
Changes in pumping are indicated on these hydrographs. Increased pumping resulted in water-level declines in the Upper Floridan aquifer at Savannah and Brunswick.
U.S. Department of the Interior |
U.S. Geological Survey
URL: http://ga.water.usgs.gov/projects/projectcoastalgwlevels.html
Page Contact Information: webmaster-ga@usgs.gov
Page Last Modified: Friday, 23-Jun-2006 11:16:42 EDT
