Groundwater is water that is stored in underground aquifers, or porous rock and soil formations. It is replenished by precipitation that seeps into the ground, and can be pumped out for use through wells. Groundwater is a critical source of water for agriculture, municipal supply, and industrial uses, especially in areas with limited surface water resources. Groundwater can be sustainable if it is managed carefully and recharged through measures such as reduced pumping, increased recharge, and improved water management practices.