People take it to the logical extreme by converting large tracts in water catching systems. Not an issue if a few do it but it usually isn’t just a few. It starts depleting aquifers and rivers, causing damage to the ecosystem and communities down the way. Doesn’t even need to be water scarce areas either.
Okay so let’s say a million acres get turned into above ground kiddie pools. These people collect and store as much water as they can, so it’s like a million acres times day ten feet deep.
How much of an effect is that water going to have on the surrounding hydrology, being trapped on those properties?
Well, it would amount to about 224 days of average flow of the Colorado River in a given year. So that would probably affect things quite a bit.