YIKES! What a nightmare!
I have heard of pools popping out from the ground. Hence, when I need to empty the pool, I make sure to do it only when it has not rained for a while. And it rains about 3 or 4 times a year here. And I never have standing water after even a hard rain. That's how gravelly my lot is, being in the foothills.
But, but, but pools floating up when there's water in them to weigh them down? Good grief.
What keeps the houses from sliding around? Maybe they do too. Why hasn't ReWahoo included this hazard in his long lists of reasons not to move to Texas?
The pools do not actually float, do they? I assume it is expansive clay that gets wet and the expands, lifting the pool up out of the ground.