In 1963 in Tuscon I recall being told by a neighbor, who happened to be a hydrologist, that Tuscon was drinking fossil water that dated to the last ice age. The Central Arizona Project was intended to provide (contested) Colorado River water for agriculture. Instead, part of it is used for cooling by the Palo Verde nuclear power plant in west central Arizona, (I don't know if some of this water is then reused for agriculture), and a significant portion is now used by Tuscon to supplement, and hopefully reduce, ground water extraction.

Tuscon bought the water rights to the Avra Valley, west of the city, and has long been extracting ground water from that bone dry desert. Traveler's accounts from the 19th century describe the Santa Cruz river, which runs through Tuscon, as having rich riverine wetland with abundant waterfowl, and the water table was to the surface. Now water only flows during significant rain events and the water table is several hundred feet lower than in 1940, depending on location, and land subsidence in excess of ten feet has been measured in south central Arizona since 1940.

In Arkansas farmers in the delta are being forced to curtail crop irrigation in some areas because of excessive water table drops. In my local area we are surrounded by lakes and rivers which serve to recharge the water table. Even so I read of the 'de-watering' of the Ozarks, though I have not seen much in the way of specifics. The hydrology was one consideration in our choice to move here.

"It is not necessary to have hope in order to persevere."