You can see what drilling is doing to it.
Nebraska has a moratorium on new irrigation wells. You however can redrill one if the first goes dry.

were concerned - they have to go deeper and deeper,
and they said they might soon reach a point where the quality of the water would not be good.
I am more concerned that the Earth's aquifers are being depleted.

"The world is perilously ignoring the water crisis that is occurring underfoot, writes Jay Famiglietti in the journal Nature Climate Change.

“Full appreciation of the importance of groundwater to the global water supply and security is essential for managing this global crisis, and for vastly improving management of all water resources for the generations to come,” he writes in an article published on October 29.

http://www.circleofblue.org/waternews/2014/commentary/editorial-in-the-circle-fresh-focus/earths-major-aquifers-trouble/

He mentions the Ogallala aquifer, and there is a chart showing depletion of major aquifers of the Earth.

The Ogallala is being drained.

and it covers pretty much the same points,
But the one I saw last nite was part of a BBC series that focuses on one town.
Course I can't remember the name of the town, but they used this town to illustrate the larger situation.
I'm frustrated that I can't find it, cuz I usually can find things, if I look hard enough.

if the name of the town comes to me (doubtful!) that will help.

thanks anyway.