Groundwater primarily comes from precipitation, such as rain and snow, that falls to the earth's surface. When this water reaches the ground, only a portion infiltrates the soil and percolates downward through the unsaturated zone until it reaches the saturated zone, where all the pores and cracks in soil and rock are filled with water. This saturated zone is known as an aquifer, and the top boundary of this zone is called the water table
. Most precipitation does not become groundwater; much of it runs off into streams, lakes, or evaporates back into the atmosphere. The water that seeps into the ground moves slowly through the soil and rock pores, eventually replenishing aquifers. This process is part of the hydrologic cycle, where water continuously changes state and location, moving from precipitation to groundwater and back to surface water through springs or seepage
. In summary, groundwater originates from surface water-mainly precipitation- that infiltrates the ground and accumulates in underground aquifers, filling the spaces in soil and rock beneath the water table
