Over the last century, the U.S. has depleted enough of its underground freshwater supply to fill Lake Erie twice, according to a new study from the U.S. Geological Survey. Here's another way to understand how much water we've used. Just between 2000 and 2008, the latest period in the study and the period of fastest depletion, Americans brought enough water aboveground to contribute to 2 percent of worldwide ocean level rise in that time.
"We think it's serious," Leonard Konikow, the U.S. Geological Survey hydrologist who performed the study, tells Popular Science. "It's more serious in certain areas."
Lowering aquifers mean less local water for the communities that depend upon them. They can also suck dry springs, wetlands and other surface water features, Konikow wrote in a report the survey published yesterday. Scientists don't always have a tally for how much water an aquifer holds, however, so it's more difficult to say what percentage of the U.S.' overall groundwater is gone.