Cisterns were driven out of popular use in the south because the open ones tended to help provide a breeding ground for mosquitoes. It caused some nasty diseases a long time ago. In some areas they were outlawed. In our area a number of folks that are not on city/county water have underground cisterns instead of wells. I guess it is cheaper to build a cistern here instead of drilling a well. Every time I have to dig a hole I wonder how far I will get before I hit a piece of rock. Record so far is 18". Usually I hit a rock (usually large flat ones) as soon as I push the shovel into the ground.