Groundwater recharge and discharge

Example of a groundwater system. Blue arrows are groundwater flow directions from the uplands to lowlands, between older and younger basin fill layers and from younger basin fill into surface-water. Red arrows are groundwater discharge from baseflow to streams, springs, well pumping, and evapotranspiration. Green arrows are recharge from groundwater flow from the upland to lowlands, rain, snowmelt, and seepage from floodwater, streams, and irrigation. Modified from Garcia and others, 2022 USGS Fact-Sheet