Aquifers are a local resource, you can think of them as somewhat like lakes that rest in depressions in geological strata rather than in depressions in the grou

Aquifers are a local resource, you can think of them as somewhat like lakes that rest in depressions in geological strata rather than in depressions in the ground. There is not one large aquifer which spans the US. As a result, the details of the situation depend greatly on the area. In the Southwest, where aquifer depletion has been a major concern, there are concerns that some aquifers may deteriorate in quality due to overextraction to the point that expensive water processing is necessary over a scale of one to two decades (e.g. along the Mexico border). It's also somewhat difficult to give a year range because there is generally not actually a cut-off point where you completely "run out" - instead, the cost of extracting and processing the water increases as overextraction continues, due to a lower water table and, worse, increased salinity. Alamogordo, NM has already initiated the construction of a desalination plant because of this problem - a very expensive proposition, and one the public rarely thinks of inland. Concern about aquifer depletion is increasing across the nation, not just in the desert southwest, but the severity of the problem varies. What is reasonably consistent is that the situation is getting worse in most places. The USGS has general information here: https://pubs.usgs.gov/fs/fs-103-03/ https://pubs.usgs.gov/fs/fs-103-03/