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Position Statement Revision

and Call for Comments

GSA members are invited to submit comments and suggestions viable twenty-first–century approaches and alternatives
regarding the following major revision of the Water Resources when developing regulations, laws, compacts, or treaties
Position Statement by 15 June 2021. Go to https://www.geosociety involving the allocation and use of these resources.
.org/PositionStatements to learn more and submit comments.
RATIONALE
WATER RESOURCES: QUANTITY Surface-water and groundwater resources are inextricably linked;
changes in one impact the other. Climate change exacerbates these
Position Summary. Population growth drives decisions about impacts by directly affecting the hydrologic cycle on local to global
water use for industrial, agricultural, municipal, and recreational scales. Increases in temperature accelerate evaporation from open
purposes. Increasing demands and a changing climate pose sig- water, soils, and vegetation. Additional water in the atmosphere
nificant, immediate challenges to ensuring sustainability of surface- combined with heat fuel extreme weather events, change water
and groundwater resources in the United States and globally. distribution patterns, intensify precipitation, decrease snowpack,
Broad, outcome-oriented water-resource science policies and and alter the timing of peak snowmelt. Temperatures in the U.S.
initiatives are needed to address these issues. increased by 0.7 °C for the period 1986–2016 relative to 1901–1960,
This position statement (1) summarizes the consensus views of with the largest increases seen in Alaska and the western U.S., and
GSA on water-resource issues, specifically the quantity of surface- projected late-century increases are even greater . Water distribu-
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and groundwater available to meet societal needs; (2) advocates tion patterns will change as climate changes, resulting in too much
improved adaptive management of the availability of existing and water in some locations and too little water in others. A changing
future water resources through collaboration of water professionals, climate coupled with mis- or un-informed policy decisions further
concerned citizens, and decision makers at all levels of government; aggravate the problem.
and (3) provides a communications tool for geoscientists. Specifically, climate change will increase the frequency,
intensity, and duration of drought in the western U.S., particularly
CONCLUSIONS AND RECOMMENDATIONS the Southwest, with adverse impacts to water resources . The
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Mitigating present-day and future, anticipated water shortages Colorado River Basin and other major river basins in the western
and managing water resources for the coming decades requires U.S. are undergoing aridification, or the ongoing, permanent
broad, sustained efforts and active collaboration among geoscien- transformation to a drier environment, to varying degrees .
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tists, engineers, water-resource managers, planners, policy makers, Impacts of droughts include reduced surface-water flow and
and industry, who should seek to groundwater storage, reduced agricultural productivity, loss of
• Improve the fundamental understanding of the quality, biodiversity, soil degradation and loss, wildfires, increases in
quantity, distribution, and use of water resources to increase invasive species and disease, and increases in heat-related human
the reliability and use of water-resource management tools. deaths . Droughts are the second costliest weather/climate-related
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Critical to this is an increased understanding of (1) the interactions disaster in the U.S. Between 1980 and 2020, 28 drought episodes
between geological, biological, and ecological systems and that resulted in more than US$1 billion in specific losses for each
quantity also refers to useable quality (water fit for human and event, with an average loss of $9.28 billion per event .
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ecological consumption); and (2) the impacts of climate change on Climate change will also lead to an increase in the frequency
the water cycle and water resource distribution, including the role and intensity of heavy rainfall events (>99th percentile of daily
of soil moisture in the hydrologic cycle, changes in type and dura- values), most notably in the Midwest and in the Northeast, where
tion of precipitation, and surface water–groundwater interaction. changes average as much as 42% and 55% (compared to data
• Increase public investment in data collection and access to available from 1958) . Additional increases exceeding 40% are
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promote efforts to improve the scientific understanding projected by the end of the century (relative to 1986–2015) . Heavy
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of water resources. A comprehensive understanding can be rainfall events lead to increased runoff, flash flooding, mudflows
achieved by maintaining current hydrologic data and monitoring and landslides, and sediment erosion and loading into the nation’s
capabilities; developing new datasets and ground- and space- waterways, all with associated impacts to infrastructure (levees,
based collection capabilities at the spatial and temporal resolu- dams, stormwater management systems, etc.) or agriculture. Long
tion needed to support model analyses and decision making from periods of heavy rainfall can also reduce the capacity of the soil
local to regional scales; organizing data collection and manage- and underlying geologic substrate to absorb water, thereby chal-
ment by surface-water and groundwater hydrologic basins; and lenging the recovery and replenishment opportunities in aquifers.
facilitating open-access to these datasets. In addition to the challenges offered by flooding events (see the
• Support computational, risk-based analyses to optimize data GSA Position Statement: U.S. Flood Risk Management), signifi-
acquisition and enhance the scientific and socioeconomic cant changes in the timing and volume of precipitation can lead
basis of decision making for water-resources management. to agricultural drought conditions (as opposed to meteorological
• Consider the natural behavior, distribution, and variability drought), where peak water availability may be out of phase with
of surface-water and groundwater resources and identify the growing season .
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44 GSA Today | May 2021