Sand is porous . . . so water can go through it. I dare you try a little experiment. Go to the beach with a Styrofoam cup, fill it up with sand (not the stuff all muddied up with twigs and algae, but the good stuff just a few feet in the water), then fill the cup up with water, then poke a hole in the bottom . . . out will come the water and not much of the sand . . . why? . . . because water can go through sand
