it's what we call the willie sutton principle. willie sutton was a bank robber and was once asked why he robbed banks, and he says, "well, that's because that's where the money is." in the same instance, the wells go in near the river because that's where the water is. but, of course, the ground-water pumping interferes with the surface-water systems. it essentially depletes surface water, and you end up with a conflict. this is a very, very limited quantity of water that you are essentially adding a lot more straws into. and ultimately what happens you run out of water. narrator: pumping a well that's near a stream creates a cone of depression that draws in water from the stream or intercepts water that would have arrived at the stream. as the demand on ground water increases, the level of surface water in streams and rivers decreases. a stream that was once gaining water from aquifers becomes a losing stream until it loses all of its water. dr. maddock: it's a physical problem in terms of the fact that you're taking water out of