If the country side continues at current rate of becoming desert, that means the cities are pumping even more water to satiate the populaces.
The Country side is the indicator.
The indication is that the cities are soon to reach the bottom of the well.
They could have drilled to Prime Water, but that was too expensive, and got in the way of taking over other Countries. Goodness me, those Municipalities have much more important things to worry about than Water.