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Thermoelectric power, irrigation, and public supply account for groundwater quantities, seasonal to decadal variations, and oppor-
90% of all surface-water and groundwater withdrawals in the U.S. tunities for storage and replenishment in the face of climate change,
(41%, 37%, and 12%, respectively) . Although many renewable drought, flooding and runoff, and anthropogenic influence.
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energy sources such as solar and wind reduce or eliminate the
need for water in electricity production, reservoir hydropower OPPORTUNITIES FOR GSA AND GSA MEMBERS
and biofuel sources may have a large water footprint . In addition, TO HELP IMPLEMENT RECOMMENDATIONS
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water is crucial for mining and processing minerals used in the To facilitate implementation of the goals of this position state-
manufacture of green technologies . ment, The Geological Society of America recommends that its
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Given the longer residence time of groundwater (compared to members take the following actions:
surface water), aquifers can be slow to respond to stresses, and • Collaborate with stakeholders (water managers, land managers,
problems may not be noticed and remedied for many years . water users, policy makers, regulators, and the public) to identify
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About 70% of groundwater withdrawals in the U.S. are used information needs and to develop sustainable water-resource
for agriculture, and the extraction rate increasingly exceeds the management goals and plans.
replenishment rate in many areas, resulting in decreased ground- • Participate in public-education activities to foster partnership
water storage . Total groundwater depletion in the U.S. from and collaboration among local, state, and federal governments;
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1900–2008 was about 1000 km , with faster depletion rates during educational and research institutions; energy, industrial, and
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2000–2008 . Two-thirds of the depletion is from the High Plains agricultural users; and the public.
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aquifer (the largest in the U.S.), the Gulf Coastal Plain aquifer • Participate in professional forums to educate peers and the public
system (Mississippi Embayment section), and the Central Valley about regional water quantity issues, including the role of climate
aquifer in California 10,11 . Sustained groundwater withdrawals and change in altering the hydrologic cycle, and identify ways that
subsequent lowering of the water table can result in the loss of better data and analyses can improve water-resource management.
connectivity with and decreased flow of surface water. Stream- • Ensure that water footprint 19,20 (both direct and indirect water
flow losses can extend far beyond the region of pumping . use) informs both personal and professional decisions every day
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Drilling deeper is not a sustainable solution; deeper aquifers tend as well as during future planning efforts.
to be more saline and require treatment, and deeper wells tend to • Improve communication with decision makers and the public
have higher construction costs and energy demands . Furthermore, about water resource availability issues. Communication is aided
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deeper aquifers may contain fossil groundwater, where recharge by analogies and examples relevant to the affected stakeholders/
could take thousands of years. populations.
Mitigating groundwater depletion will require reducing demand,
particularly in irrigated agriculture, and increasing supply through REFERENCES CITED
artificial aquifer recharge and other methods . Efforts at the munic- 1. USGCRP, 2018, Impacts, Risks, and Adaptation in the United States:
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ipal level to capture stormwater and use gray water can enhance Fourth National Climate Assessment, Volume II. Reidmiller, D.R., C.W.
local water supplies and show promise for sustainable urban water Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and
B.C. Stewart, eds., U.S. Global Change Research Program, Washington,
management . Any mitigation strategy is complicated by the fact DC, USA, 1515 p., https://doi.org/10.7930/NCA4.
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that local groundwater conditions can be highly variable and cross 2. Vose, R.S., D.R. Easterling, K.E. Kunkel, A.N. LeGrande, and Wehner,
geopolitical boundaries. Scientific and technical issues are often M.F., 2017, Temperature Changes in the United States. Climate Science
coupled with political, legal, and socioeconomic considerations and Special Report: Fourth National Climate Assessment, Volume I. Wueb-
constraints . Given these complexities, we must recognize that one bles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K.
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Maycock, eds., U.S. Global Change Research Program, Washington, DC,
technical approach is not appropriate for all aquifers, and solutions USA, 185–206, https://doi.org/10.7930/J0N29V45.
will require comprehensive and integrated analysis and discussion. 3. Colorado River Research Group, 2018, When is drought not a drought?
Comprehensive and robust datasets with high spatial and tempo- Drought, aridification, and the “new normal,” 4 p. https:// www. colorado
ral resolution, including basin- and aquifer-scale geophysical data river researchgroup .org/ uploads/4/2/3/6/42362959/crrg_aridity_report.pdf.
and three-dimensional geologic maps are needed to inform ground- 4. National Drought Mitigation Center, 2020, Are you impacted by drought?,
https://drought.unl.edu/ranchplan/DroughtBasics/ AreYouImpacted byDrought
water modeling and address the issues outlined above. The U.S. .aspx.
Geological Survey (USGS) has developed and maintained extensive 5. NOAA National Centers for Environmental Information (NCEI), 2020, U.S.
surface- and groundwater monitoring networks and databases such Billion-Dollar Weather and Climate Disasters, https://www.ncdc.noaa.gov/
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billions/.
as the National Hydrography Dataset , but gaps in coverage and 6. National Drought Mitigation Center, 2020, Types of drought, https://
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data remain ; the USGS is currently developing a Next Generation drought.unl.edu/Education/DroughtIn-depth/TypesofDrought.aspx.
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Water Observing System (NGWOS) that will address these gaps 7. Dieter, C.A., Maupin, M.A., Caldwell, R.R., Harris, M.A., Ivahnenko, T.I.,
and eventually “provide high temporal and spatial resolution data Lovelace, J.K., Barber, N.L., and Linsey, K.S., 2018, Estimated use of water in
on streamflow, evapotranspiration, snowpack, soil moisture, water the United States in 2015: U.S. Geological Survey Circular 1441, 65 p., https://
doi.org/10.3133/cir1441. [Supersedes USGS Open-File Report 2017-1131.]
quality, groundwater/surface-water connections, stream velocity 8. Jin, y., P. Behrens, A. Tukker, and L. Scherer, 2019, Water use of electricity
distribution, sediment transport, and water use .” At regional and technologies: A global meta-analysis, Renewable and Sustainable Energy
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global scales, satellites such as the Gravity Recovery and Climate Reviews, 115. https://doi.org/10.1016/j.rser.2019.109391.
Experiment (GRACE) launched in 2002 and GRACE Follow-On 9. Mudd, G.M., 2008. Sustainability reporting and water resources: a pre-
(GRACE-FO) launched in 2018 provide terrestrial water storage liminary assessment of embodied water and sustainable mining, Mine
information based on changes in Earth’s gravitational field . Water and the Environment, 27, p. 136–144, https://doi.org/10.1007/
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s10230-008-0037-5.
Such data combined with ground- and model-based approaches 10. Konikow, L.F., 2015, Long-Term Groundwater Depletion in the United
are critical for understanding causes and variations in surface- and States, Groundwater, v. 53, p. 2–9.
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