How is groundwater recharged?
Groundwater recharge occurs when rain, snowmelt or surface water infiltrates through soil and reaches the water table.
Formation process and geographic mechanism
Some water is used by plants or evaporates, while the remainder percolates through pores and fractures. Permeable sand and gravel recharge rapidly, whereas clay slows flow. Mountain fronts, temporary streambeds and karst fractures may be important recharge zones. Water-table response can lag rain by days, months or years.
Spatial outcomes, measurement and management
Paving can reduce infiltration and increase runoff, while recharge basins or suitable wells can direct excess water underground. Quality control is essential because contaminants travel by the same routes. Sustainable pumping is compared with long-term recharge and ecosystem connections. A short water-level rise does not prove a safe permanent yield.