Dear 100 Hour Board,
Does Provo sit on top of some kind of aquifer or underground lake? Some doomsday-sayer seems to think it does, and that one day Provo will collapse into it.
According to this article, northern Utah Valley does have a nice aquifer, but it's not really an underground lake—more like water in a bunch of sand and gravel. I haven't been able to find any signs that we're in danger of land subsidence, but it could happen (and is happening in other places) if we use up too much of the groundwater. Mind you, this wouldn't be a sudden collapse, but rather a gradual sinking of land that causes cracks in roads and pipes. So never let the water run and be grateful tunnel worms drink blood instead of water.