Water Underground

How does water move underground? Water trickles down between particles of soil and through cracks and spaces in layers of rock Different types of rock and soil have different sized spaces The size of the pores and the connections between them, determines how easily water moves

Permeable? Soil and rock that allows water to pass through is called permeable Other materials like clay have very small pores, so water cannot pass through Materials that water cannot pass through are called impermeable

Water Zones When water from precipitation, passes down through permeable rock, the ground begins to saturate When the water gets deep enough it reaches the saturated zone, where the pores are full The top of the saturated zone is called the water table

How do people use groundwater? An underground layer of permeable rock that holds water and allows it to flow is an aquifer The huge Ogallala aquifer reaches from South Dakota all the way into Texas People can get water from an aquifer by drilling a well below the water table

Pumps and Pressure An artesian well is where water rises on its own because of pressure within an aquifer Water becomes trapped between two layers of impermeable rock and the pressure builds until that rock is punctured