A U.S. Geological Survey report released Monday finds that from 1900 to 2008, U.S. aquifers are being depleted by more than twice the volume of water found in Lake Eerie alone.
USGC explains the situation in its report, Groundwater Depletion in the United States 1900-2008. The report examines 40 aquifers in the U.S. based on previous studies and current evaluations.
In a statement, Suzette Kimball, acting USGS Director, explained that groundwater stored in aquifers provides drinking water, supports irrigation and industry, sustains the flow of streams and rivers, and maintains ecosystems.
"Because groundwater systems typically respond slowly to human actions, a long-term perspective is vital to manage this valuable resource in sustainable ways," Kimball said. The study examines the changing groundwater levels in relation to industrial, agricultural and municipal use.
Latest study on long-term aquifer water levels finds accelerating draw-down
While draw-down has increased significantly since 1950, higher rates have occurred from 2000-2008, averaging 25 cubic kilometers per year. The historical average is 9.2 cubic kilometers per year, USGC said.
In addition to the rapid draw-down experienced over the last 100 years, groundwater depletion in the U.S. from 2000-2008 explains more than 2% of the observed global sea-level rise during that period.
Specifically at risk, the USGC notes, is the Ogallala Aquifer, located across 170,000 square feet under the High Plains. The study finds that depletion during the last eight years alone amounts to 32% of the cumulative depletion of the aquifer during the entire 20th century.
The Ogallala is used heavily for agricultural irrigation, the USGC said, accounting for water table declines that exceed 160 feet in some areas.
The latest study expands on information collected and presented in a USGC survey released earlier this year focusing on the Ogallala draw-down.
Read the report, Groundwater Depletion in the United States 1900-2008.