Groundwater is nearly the sole source of fresh drinking water in Maryland's Coastal Plain (area east of I-95). Approximately 1.4 million people rely on groundwater in the Coastal Plain. While ground water is not used as much as surface water as a water source, some towns and most domestic users in central and western Maryland also rely heavily on groundwater. Aside from being a crucial drinking water source, groundwater is also important for irrigation, commercial and industrial uses, and power plants (thermoelectric).
In 2000, the primary use of groundwater in Maryland was for public supply followed by domestic (self-supplied use). Irrigation was the third largest use of groundwater in the State, however in the subsequent years irrigation has increased significantly (primarily on the Eastern Shore). Commercial and industrial use withdraw about equal amounts of water followed by livestock watering, mining, and thermoelectric use.