A new Council of Agricultural Science and Technology, or CAST, paper examines the causes and consequences of groundwater depletion throughout the U.S. with a focus on how this will affect agriculture — the largest sector of groundwater use.
The paper, “Aquifer Depletion and Potential Impacts on Long-term Irrigated Agricultural Productivity,” was co-authored by Dr. John Tracy, Texas A&M University’s Texas Water Resources Institute director, College Station.
Tracy chaired a task force of university and government researchers exploring the long-term impact of aquifer depletion on U.S. agriculture. Their investigations and insights are reflected in the paper.
Additional members included Dr. Jennifer Johnson, Bureau of Reclamation River and Reservoir Operations, Boise, Idaho; Dr. Leonard Konikow, U.S. Geological Survey, retired, Reston, Virginia; and Steve Sibray, University of Nebraska-Lincoln, Institute of Agriculture and Natural Resources.
Paper highlights include:
- An overview of groundwater and its use in the U.S.
- An outline of geographical areas impacted by groundwater use.
- Consequences from depleting aquifers.
- Mitigation efforts to reverse groundwater depletion.
- A case study on the causes, consequences and mitigation of groundwater depletion.
According to the paper, large-scale depletion of groundwater within the U.S. began in the 1950s and tripled by the 1990s, with approximately 71 percent directed toward irrigating crops, Tracy said.
The paper noted the U.S. aquifer system with the greatest long-term groundwater storage depletion is the Ogallala Aquifer in the Great Plains region, where groundwater levels have declined by more than 150 feet in some areas.
Strategies to mitigate impacts of aquifer depletion may include policy, technology and management options, which should take into account local/regional conditions, including hydrogeological factors, applicability to agricultural production systems and economic factors, Porter said.
Sheng said while some solutions can be simple, such as decreasing or stopping pumping or increasing water availability with managed aquifer recharge, no one solution fits all.
“To be more effective, they should be essential components of integrated water resources management, which considers policy constraints and social and economic impacts beyond technical feasibility,” he said.
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