I heard part of this water story on NPR today while in the car. I was in the car a lot today.

Has anyone talked about the Ogallala Aquifer? I am particularly worried because of fracking. I haven’t heard one peep about it under any context.

About 27 percent of the irrigated land in the United States overlies the aquifer, which yields about 30 percent of the ground water used for irrigation in the United States. Since 1950, agricultural irrigation has reduced the saturated volume of the aquifer by an estimated 9%. Depletion is accelerating, with 2% lost between 2001 and 2009[2][not in citation given] alone. Once depleted, the aquifer will take over 6,000 years to replenish naturally through rainfall.[3]

The aquifer system supplies drinking water to 82 percent of the 2.3 million people (1990 census) who live within the boundaries of the High Plains study area.[4]

Wiki lists the world-wide aquifers here.