Climate Change Impacts to Groundwater, Springs Hydrology and
Aquatic Communities
Amargosa Desert and Death Valley National Park, Nevada and California
1
1
1
2
Terry Fisk , Greg Pohll , Don Sada , Mark Stone
1
Desert Research Institute, Division of Hydrologic Sciences, Reno, NV
2
University of New Mexico, Department of Civil Engineering, Albuquerque, NM
INTRODUCTION
METHODS
Springs are created where groundwater reaches the surface through natural processes. They provide much of the
aquatic wetland environment in arid lands as well as a substantial portion of regional aquatic and riparian biodiversity. Arid land springs are distinct from springs in more humid regions because they are typically isolated,
more susceptible to climate change, and are strongly influenced by aquifer characteristics. However, insight into
how aquatic and riparian communities will respond to climate change is currently limited to speculation.
At least one dozen springs in the Furnace Creek province of Death Valley National Park, including Travertine
Springs, historically flowed onto the floor of Death Valley. These springs are the terminal discharge points for the
lower carbonate aquifer, a regional aquifer of approximately 100,000 km2 underlying much of southern Nevada.
The National Park Service has recently changed the delivery system for Furnace Creek water so that direct diversion from Travertine Springs has ceased. Instead, domestic water is pumped from wells upgradient from Travertine Springs and irrigation water will be collected from downgradient infiltration galleries. This change provides an ideal study platform for research into spring ecology and the effects of changing flow regimes – analogous to conditions that may be seen in response to climate change.
FUTURE WORK
Climate Impacts
The Southwestern U.S. faces general temperature increases with largest warming in the summer months, and a
likely decrease in precipitation. Due to the aridity of southern Nevada and Death Valley, small changes in water
availability may translate into significant alterations in evapotranspiration, recharge, and runoff. Projections for
changes in recharge (and also temperature, evapotranspiration, and precipitation) will modify boundary conditions of the groundwater and ecological models, described below.
Annual precipitation
and ground water recharge
Springs in Ash Meadows National Wildlife Area in the Amargosa Desert are intermediate discharge points from
the lower carbonate aquifer. The combination of decades of spring discharge and water level data from Furnace
Creek, Ash Meadows, and Devils Hole (adjacent to Ash Meadows), new Furnace Creek production and monitoring wells, and monitoring networks in the Amargosa Desert provide a very suitable infrastructure to evaluate
how aquifer dynamics and spring discharge may be affected by climate change.
Groundwater Modeling
A groundwater flow model will be developed for portions of the Amargosa Desert and Travertine Springs area
to evaluate affects on the groundwater flow system resulting from climate change. The model will be based on
the U.S. Geological Survey Death Valley Regional Groundwater Flow System model. Simulations will be conducted to evaluate how changes in climate, expressed primarily as changes in recharge, affect spring discharge.
In addition, response of the aquifer and Travertine Springs to pumping from production wells located upgradient from Travertine Springs will be simulated as an analogue for potential future reduction in spring discharge
caused by climate change.
LOCATION
The specific model domain remains to be selected, as well as how the local model will be embedded
within the existing U.S. Geological Survey model. Options include (1) a very localized model focusing on
the Travertine Springs/Furnace Creek area of Death Valley, and (2) a domain encompassing the southern
portion of the Amargosa Desert, including Ash Meadows and Devils Hole.
Death Valley National Park and the National Park Service Water Rights Branch in Fort Collins, Colorado
have been collecting spring discharge and groundwater level data for decades from Travertine Springs and
other springs in the Furnace Creek area, and from a variety of monitoring well networks inside and outside the park. In addition, the park has been collecting water level and pumping data from the new production wells, and associated monitoring wells since the advent of pumping. These data will form the core
set that will be used to model changes to the local groundwater flow system and spring discharge, and to
better define aquifer characteristics in the vicinity of Travertine Springs. Data from a variety of monitoring well networks in the Amargosa Desert and from Devils Hole will be used in the groundwater flow
model for both steady-state and transient calibration, and to evaluate potential climate-related changes in
water levels in the Amargosa Desert and Ash Meadows areas.
Example: Map of hydraulic conductivity bases on
lithologic properties, aquifer test data, and water
level monitoring data.
Example: Travertine Spring water column
analyses for macroinvertebtates.
Amargosa Desert
Amargosa Desert
Travertine Springs
Travertine Springs
Ash Meadows
Spring Mountains
REFERENCES
“How will aquatic ecosystems respond to climate change, and can we develop a quantitative
understanding of groundwater – spring dynamics so that we may predict changes to aquatic
ecosystems?”
Understanding how spring ecosystems respond to climate change is the initial requirement in being able to
develop predictive models of these ecosystems. Our overall hypothesis presumes that climate change in
southern Nevada will result in decreased precipitation, increased temperatures, increased evapotranspiration, and a decrease in recharge to the groundwater system (IPCC 2007). Further, we assume that a reduction in spring discharge will occur because of decreased groundwater recharge, and this reduction in discharge will affect dependent aquatic ecosystems.
Abundance
RESEARCH QUESTION AND HYPOTHESIS
Proportion
Recharge to the Lower Carbonate Aquifer is primarily from precipitation in the higher mountains of southern Nevada. For Ash Meadows, the Amargosa Desert, and Travertine Springs, a substantial portion of recharge is from the Spring Mountains. Additional recharge is from Pahute Mesa and the Sheep Range.
Ecological Modeling
Changes in the aquatic environment affecting benthic macroinvertebrate abundance and community structure
will be examined by quantifying physical characteristics of the spring brook environment during full discharge
and at several lower discharge rates. We will utilize a physical habitat model to determine discharge rates that
sustain habitats that support the existing benthic macroinvertebrate assemblage structure. We will integrate
field experiments and habitat modeling to quantify thresholds where decreases in discharge affect the abundance and distribution of benthic macroinvertebrates, and the structure of this community.
Meters From Source
Endemic macroinvertebrates, excluding spring snails
NonEndemic macroinvertebrates, excluding spring snails
Meters From Source
Belcher, W. R. (ed.) 2004. Death Valley regional ground-water flow system, Nevada and California – Hydrogeologic framework and transient ground-water flow model: U.S. Geological Survey Scientific Investigations
Report 2004-5205, 408 p.
Hershler, R. and D.W. Sada. 2002. Biogeography of Great Basin freshwater snails of the genus Pyrgulopsis. Pages
255 – 276. In, R. Hershler, D.B. Madsen, and D.R. Currey (eds.). Great Basin aquatic systems history. Smithsonian Contributions to Earth Sciences, Number 33.
Sada, D.W. and D.B. Herbst. 2006. Ecology of aquatic macroinvertebrates in Travertine and Nevares Springs,
Death Valley National Park, California, with an examination of water diversion effects on their abundance and
community structure. Unpublished report to U.S. National Park Service, Death Valley National Park.
Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor, and H. Miller, eds. 2007. The
Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York,
NY, USA.
Stonestrom, D. A., Constantz, J., Ferré, T.P.A., and Leake, S.A., eds. 2007. Ground-water recharge in the arid and
semiarid southwestern United States: U.S. Geological Survey Professional Paper 1703, 414 p.
Winograd, I. J., and W. Thordarson. 1975. Hydrogeologic and hydrochemical framework, south-central Great Basin, Nevada-California, with special reference to Nevada Test Site. U.S. Geological Survey Professional Paper
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ACKNOWLEDGEMENTS
This research is funded by the National Science Foundation Nevada EPSCoR Program under Cooperative Agreement No. EPS-0814372. We
are grateful to the National Park Service and U.S. Geological Survey for their support with data acquisition and modeling.