What is an aquifer? Well, when it rains, water seeps into the ground and collects in porous rock deep under the surface. That is an aquifer. We can get that water by drilling a well to pump it to the surface. It is like a water bank! When we can’t get enough water from our rainfall, rivers and lakes, we go to the aquifer. But we don’t want to take too much water, because it takes a VERY LONG TIME for the aquifer to refill. So we sure do want to save our aquifers!