Groundwater.
https://www.emergency-wash.org/water/en/technologies/technology/groundwater
👉🏼 PDF: https://app.box.com/s/89nbpf6psvmku50zhdc4qrterbz38ype ___ Groundwater originates from both surface water, such as rivers or lakes, and via precipitation that infiltrates the surface. This infiltration is mostly natural, though can be enhanced through managed aquifer recharge techniques. Once in the ground, water collects in the spaces between particles and can flow slowly. This saturated area that allows water movement is called an aquifer, which can be either unconfined (open to atmospheric pressure) or confined (under greater pressure than atmospheric pressure). Groundwater is useful in all phases of an emergency.