Groundwater: Solution to the Las Vegas Water Problem? Rosa Perez1 and Christopher A. Ruiz1 1University of Nevada Las Vegas SCI 101 Ms. Alicia Simon, Adviser

Abstract

A contentious debate is taking place in different sectors of the community on how to manage the stateʼs groundwater system. It is a battle whose outcome, regardless of who wins, will have a tremendous impact on the future of Las Vegas. Economic benefits always seem to downplay environmental considerations in the policy-making process, often with serious consequences. This paper takes a superficial look at the SNWAʼs Groundwater Development Project and discusses the issues for and against it. Groundwater is abundant, accessible and cheap but exploitation and over-pumping can have serious environmental effects, as well. It is our hope that the issues presented here will lead to more open dialogue so that an equitable solution to Las Vegasʼ water problem can be reached.

Introduction

The explosive growth in Las Vegas has resulted in an unprecedented demand for more water (Figure 1). The Colorado River accounts for 90% of its water supply while the Las Vegas Valley groundwater basin provides the remaining 10% (Figure 2). Data collected by the USGS in 2005 showed that the two sources together accounted for some 240,000 acre-feet of water that was consumed in Nevada (“USGS: Data Files”). The water supply, however, has not been able to keep pace with one of the fastest population growths in the nation.

The problem is compounded by declining water levels in the two primary reservoirs at Lake Mead and Lake Powell due to the effects of global warming and the increased demands on an already stressed river system. Drought conditions in the river began in 1999, hit critical levels in 2002 and persists to this day (“Water Resource Plan” 9). This prompted policymakers and water managers to draw up plans contained in the Southern Nevada Water Authorityʼs (SNWAʼs) Groundwater Development Project that would decrease reliance on the Colorado River by developing primarily groundwater or “non-river, in-state” resources. A major component of this project will require transporting groundwater from the northeastern part of the state to Las Vegas. It takes a proactive stance on the water situation and yet, raises a serious ethical question due to perceived lack of concern for environmental and conservation issues.

Advantages of Groundwater Development

Ethical Question

Disadvantages of Groundwater Development

While the benefit of having a suitable supply of water in drought-stricken Las Vegas is quantifiable, the risk to the environment is priceless. The question, “Should residents of Las Vegas pursue proposals for extensive groundwater development to meet future water needs?” becomes relevant from an environmental perspective. This is a sensitive issue that requires a thorough and relevant study of the pros and cons which, hopefully, will provide the common ground in the formulation of a clear-cut policy on groundwater development.

Conclusion

Bibliography

To meet increasing demands in Las Vegas, the SNWA applied for water rights in Lincoln and White Pine counties to facilitate “large-scale groundwater withdrawal” for current and future needs (Williams et al. 689). SNWAʼs Water Resource Plan: The plan will add about 134,000 acre-feet of water annually to the stateʼs water reserves, augmenting the 300,000 acre-feet annual diversion from the Colorado River (vi). Reliance on surface water from the Colorado River is expected to decrease (Figure 2). The SNWA believes that any unused water that is kept in the lake will only benefit the river system in the long run. Studies conducted by the USGS show that groundwater provides about 97% of available freshwater in the region which is more than what is in rivers and lakes. It is abundant, of fairly good quality and has low-cost--benefits that make it attractive to water planners. It is easily accessible where there is need for it, making it a very important component of any management plan to Las Vegasʼ water problem. It comes as no surprise that in Las Vegas, as in other places in the nation, groundwater finds the greatest utility for public and domestic purposes, as well as thermoelectric power generation and irrigation (Figure 3).

Environmental issues are beginning to take a foothold in todayʼs society so that decisions are made not only to address immediate concerns but far-reaching ones as well. The urge to provide remediation to Las Vegasʼ water problem is strong but as we have learned, there is a need to temper them with judgement that seeks a common ground. It is important to be cognizant of environmental constraints on the decision-making process. Water is a very valuable natural resource. In Las Vegas, demand is increasing at an alarming rate but supply is limited.

When one considers the possibility that both surface and ground water resources may be depleted someday, it is only fair to adopt contingencies that highlight conservation rather than waste. The National Water Research Institute (NWRI) believes that measures encouraging “turf reduction and xeriscaping, water recycling, incentive pricing and billing and equipment upgrade (for example, faucets, pipes, washing machines)” can have tremendous impact on the way that water is used in this region (Blomquist 5). When these measures were adopted by water planners in Las Vegas, the NWRI reported “a 13 percent drop in per capita water use” in the area (Blomquist 4). This means conservation measures are effective and it can be done.

Finally, the SNWA Groundwater Development Project should be pursued as a last resort to ensure a stable water supply but every effort must be taken to prioritize environmental concerns over the future needs of Las Vegas. We are only stewards of this planet and not its owners. We have an obligation to protect and conserve its resources for future generations.

Blomquist, William A. “Water 2010: A "Near Sighted" Program of Water Resource Management Improvements for the Western United States.” Fountain Valley, CA: National Water Research Institute, 2007. Print.

Bredehoeft, J. "Impacts of Proposed SNWA Groundwater Development in Cave, Dry Lake, and Delamar Valleys, White Pine and Lincoln Counties, Nevada." Nevada Division of Water Resources. N.p., n.d. Web. 15 Mar. 2011. <water.nv.gov/hearings/dry_cave_delamar%20hearings/ACE/Initial%20Evidentiary%20Exchange/Exhibit%201130.pdf>.

"Gone to the Well Too Often." Trout Unlimited, n.d. Web. 12 Mar. 2011. <www.tu.org/atf/cf/%7B0D18ECB7-7347-445B-A38E-65B282BBBD8A%7D/ground%20water%202ed_lores.pdf>.

"Groundwater use in the United States." USGS Georgia Water Science Center - Home page. USGS. 14 Mar. 2011 <http://ga.water.usgs.gov/edu/wugw.html>.

Leake, S.A.. "Land Subsidence From Ground-Water Pumping." Climate Change Research in " the U.S. Geological Survey. N.p., n.d. Web. 16 Mar. 2011. <http://geochange.er.usgs.gov/sw/changes/anthropogenic/subside/>.

Llamas, M. Ramon, and Alberto Garrido. "Lessons from Intensive Groundwater Use In Spain: Economic and Social Benefits and Conflicts." The Agricultural Groundwater Revolution: Opportunities and Threats to Developments and Conflicts. Sri Lanka: CAB International, 2007. 266-295. Print.

Morris, Robert Ll, and Dale A. Devitt. "Urbanization and Water Conservation in Las Vegas Valley." Journal of Water Resources Planning and Management 123.3 (1997): 189. Academic Search Premier. EBSCO. Web. 19 March 2011.

“The Hydrologic Cycle.” 2007. Ground Water Protection Council, USA. Ground Water: A Call to Action. Web. 12 Mar. 2011.

"USGS: Data Files for Estimated Use of Water in the United States, 2005." USGS Water Resources of the United States. N.p., n.d. Web. 16 Mar. 2011. <http://water.usgs.gov/watuse/data/2005/>.

“Water Resource Plan.” Water Resources. Version 2009. SNWA n.d. Web. 7 Mar. 2011. <www.snwa.com/assest/pdf/wr.>

"Water Science for Schools: Groundwater quality." USGS Georgia Water Science Center - Home page. N.p., n.d. Web. 19 Mar. 2011. <http://ga.water.usgs.gov/edu/earthgwquality.html>.

Williams, Jack E., et al. "Fueling Population Growth in Las Vegas: How Large-scale Groundwater Withdrawal " Could Burn Regional Biodiversity." BioScience 57.8 (2007): 688-698. Academic Search Premier. EBSCO. Web. 19 Mar. 2011.

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Water rights to unappropriated groundwater in the northeastern counties of Nevada are still pending before the State Engineerʼs office. Opposition to the SNWAʼs Groundwater Development Project stems from concerns that the proposal fails to appreciate the consequences of withdrawing close to 200,000 acre-feet of groundwater annually on the environment. The scientific community reacted adversely to pronouncements by the SNWA in 2006 that it was “difficult to predict” how the system would respond due to “lack of hydrologic data,” citing scientific literature to bolster their claim (Bredehoeft 3). The principal investigator of the study in question later came out to refute that claim and offered additional information that showed the vast interconnection between the different carbonate aquifers in Nevada (Bredehoeft 4). The implications of a vast, “interconnected groundwater system” only heightened opposition to the project, resulting in the withdrawal by the water authority of some water rights applications “to accommodate rural interests” (Williams et al. 692).

Environmentalists were also concerned that the huge amount extracted from the groundwater system would lead to “over-drafting” and a decline in levels over time (Morris 190). In the Las Vegas Valley where recharge rates are often limited, this problem can be even more severe. Conceptual models that showed “projected groundwater level declines of about 0.3 to 488 m throughout 78 basins...” were used to support this assertion (Williams et al. 692).

Figure 2: Additional water resources can sustain demands until 2060 and increase non-river sources by up to 40% (right) from the 10% (left) where it currently stands (“Water Resource Plan” vii).

Colorado River

Groundwater

Current Supplies

Colorado River

Groundwater

Future Supplies

0

225

450

675

900

Thermoelectric Irrigation Public Domestic

Groundwater Freshwater

Domestic

Public Supply

IrrigationMining

Thermoelectric

Figure 3: Water use in the whole state of Nevada (right) compared to Las Vegas (left). Source: USGS: Data Files, 2005.

According to the USGS, groundwater is free of “particulate matter, such as leaves, soil, and bugs...” because of the earthʼs natural filtration system, making it cheaper to maintain and readily available for use barring significant contamination (“Groundwater Quality”). One of groundwaterʼs more attractive properties is its “reliability in dry seasons or droughts” because of a large pool stored below ground that is essentially free from the effects of evaporative loss (“World Water Day 1998”). In arid regions such the Southwest where afternoon temperatures in the summer can be brutally high, groundwater can provide a stable reserve over time.

Investigators believe that these declines may persist “over the next 100 years, and may not stabilize before failing” (Williams et al. 692). Low levels of groundwater would then lead to “lower base flow in rivers and streams... disrupting spring and wetland communities” (Williams et al. 689).

A serious consequence of groundwater “over-pumping” led to the “extinction of the Las Vegas dace (Rhinichthys deaconi)” in the late 1950s when its natural habitat dried up (Williams et al. 690). The fear is that more species of aquatic organisms will meet similar fates if exploitation of the groundwater system is left unchecked.

Decline in groundwater levels can also increase susceptibility to ”valley-wide subsidence,” causing land surface to collapse or sink on itself (Morris 190). A study by Leake for the USGS demonstrated localized subsidence of 6 feet for Las Vegas (“Land Subsidence From Ground-Water Pumping”). Lastly, “over-withdrawal” has been shown to degrade water quality and decrease availability for farmers in rural communities (Llamas et al. 281).

The Hydrologic Cycle

“The Hydrologic Cycle.” Image courtesy of the Groundwater Protection Council. MEASURING WATER

According to Trout Unlimited’s Western Water Project, one acre-foot of water contains 325,850 gallons which would flood a football field 1 foot deep. Depending on where someone lives in the West, a family of four uses on average, between one quarter and one half an acre-foot per year.

Figure 1: Population growth and consumptive use of water in Las Vegas from 1985-2005 Source: USGS Data Files.