Drought-trigger ground-water levels and analysis of historical water-level trends in Chester County, Pennsylvania

The Chester County observation-well network was established in 1973 through a cooperative agreement between the Chester County Water Resources Authority (CCWRA) and the U.S. Geological Survey. The network was established to monitor local ground-water levels, to determine drought conditions, and to monitor ground-water-level trends. Drought-warning and drought-emergency water-level triggers were determined for 20 of the 23 wells in the Chester County observation-well network. A statistical test to determine either rising or declining water-level trends was performed on data for all wells in the network. Water-level data from both of these wells showed a rising trend. A decrease in ground-water pumping in the area near these wells was probably the reason for the rise in water levels.