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Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

PNAS

By:
, , , , , , and
DOI: 10.1073/pnas.1200311109

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Abstract

Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ~50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ~7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley
Series title:
PNAS
DOI:
10.1073/pnas.1200311109
Volume
109
Issue:
24
Year Published:
2012
Language:
English
Publisher:
National Academy of Sciences
Contributing office(s):
California Water Science Center
Description:
6 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
PNAS
First page:
9320
Last page:
9325
Country:
United States
Other Geospatial:
High Plains;Central Valley