That sounds totally plausible. Do you know in which regions have fossil aquifers, and which have aquifers with reasonable inflow? Also, I don't immediately see

That sounds totally plausible. Do you know in which regions have fossil aquifers, and which have aquifers with reasonable inflow? Also, I don't immediately see why depleting a fossil aquifer would be bad (as opposed to using coal or oil, which affects CO2 levels). Do I miss any side effects? If not, it might be reasonable to use fossil water as long as it is available to make a region liveable, but restrict its use for e.g. agriculture, to make the water last longer.