I didn't realize how fast water levels in aquifers are falling:
Water Waste May Leave Us Thirsty, by David Biello, Scientific American: Since 1900, the U.S. has pulled enough water from underground aquifers to fill two Lake Eries. And in just the first decade of the 21st century, we've extracted underground water sufficient to raise global sea level by more than 2 percent. We suck up 25 cubic kilometers of buried water per year.
That's the message from the U.S. Geological Survey's evaluation of how the U.S. is managing its aquifers. Or mismanaging. For example: water levels in the aquifer that underlies the nation's bread basket have dropped in some places by as much as 160 feet.
The rest of the world isn't doing any better. ... Mismanagement of water resources is a hallmark of this new human-dominated era in the Earth's geologic history, known as the Anthropocene. Despite building, on average, one large dam every day for the last 130 years, we use more water than we store. And we're letting that freshwater escape to the seas. Which means we may find ourselves with water, water everywhere, but not much fit to drink.