Authors Christian Harrison

The Final Intake: Las Vegas’s Search for Water Security

Assembled Intake Structure being transported across Lake Mead. Courtesy of SNWA
Assembled Intake Structure being transported across Lake Mead. Courtesy of SNWA

By Christian Harrison

On December 10, 2014, the Southern Nevada Water Authority (SNWA) reached a major milestone. On that day a massive, six-hundred foot long boring device finished digging a three mile tunnel, two hundred yards underneath the surface of Lake Mead. The tunnel is part of a new water intake system and comes up through the bottom of the lakebed. The concept is similar to the drain in a bathtub—SNWA engineers specifically adopted this design feature to access Colorado River water no matter how low Lake Mead dropped. The pipeline was designed for an extreme environmental eventuality that, at the time of writing, seems increasingly likely to occur. Begun in 2005, the third intake was built specifically in response to the increasingly severe drought gripping the entire Colorado River Basin.

Shortly after the beginning of the twenty-first century, the SNWA board realized the Las Vegas metropolitan area needed a more reliable means of withdrawing water from Lake Mead. They knew the drought could potentially render the SNWA’s existing infrastructure obsolete in only a few years. In 2008, climate scientists Tim Barnett and David Pierce, working for the Scripps Oceanographic Institute, predicted there was a fifty-percent chance Lake Mead would go dry by 2021.[1] Under this scenario the electric generating turbines at Hoover Dam would cease turning, and a much-diminished Colorado River would flow where Lake Mead used to be. Reinforcing Barnett and Pierce’s prediction, in 2015 Deputy Secretary of the Interior Michael Connor announced he would likely be forced to impose mandatory rationing of Colorado River Water to Nevada and Arizona as early as the following year. This announcement merely confirmed what SNWA officials already knew—the Colorado River Basin was drying out, and Las Vegas’s access to its primary water supply was increasingly threatened.

Water levels at Hoover Dam in 1983 and 2013. Courtesy of SNWA
Water levels at Hoover Dam in 1983 and 2013. Courtesy of SNWA

Water levels in Lake Mead began to drop in 1999, a trend that, at the time of writing, has not yet abated. Scientists who study the region and officials within the Colorado River Basin believe the drought is far from over. Chief among these individuals is Patricia Mulroy. By 2002, Mulroy had adopted a pessimistic, yet proactive philosophy toward water management. In an April board meeting she told her staff “we’ve got to have a plan. We have to live twenty or thirty years in the future, and we have to assume the worst.”[2] Her views are consistent with several scientists who argue that the Basin has entered a mega-drought, a phenomenon that has occurred before and in some instances had lasted up to forty years. The existing science and Mulroy’s recommendation provided the impetus to build additional infrastructure.

The drought has exposed the weakness of the SNWA’s existing infrastructure. There are only two intake structures in place to withdraw all the water the metropolitan area needs, and they are in danger of becoming inoperable. Diminishing lake levels are making the problem increasingly obvious. In April 2015, Lake Mead dropped to an elevation of 1,080 feet.[3] The SNWA only has thirty more feet before it loses its first intake. If and when lake levels decrease to 1,050’, intake number one will begin sucking air. After that, the entire metro-area will be entirely reliant upon a single intake (intake no. 2), which sits at 1,000 feet.[4] And even that may be inadequate. Evidence suggests that Lake Mead could decrease in size to below 1,000 feet in the next decade.

Climate trends convinced the SNWA board that without a third intake, one much lower into the lake, two million people could lose access to their drinking water supply. Acting on Mulroy’s recommendation, in 2004 the board initiated the planning process for the new intake. Two primary considerations influenced the design of the third intake. The first was ensuring access to water no matter how low lake levels became. As previously noted, the lake could very well disappear in the coming decades. The design needed to be able to obtain water no matter how low water levels got, even if there was only a river.

Courtesy of SNWA

Second, the SNWA needed to guarantee access to a clean water supply. As the volume of water in Lake Mead decreased, the concentration of pollutants increased. The metropolitan area disposes of its sewage into Lake Mead via the Las Vegas wash. The wash debouches upstream of the first and second intake. Historically, this has not been an issue since the treated sewage is relatively warm and floats on the surface of Lake Mead. The SNWA typically withdraws water from the cooler and deeper depths of the lake. At the beginning of the twenty-first century, however, the distance between these two levels became increasingly small, evening out the temperature between the two. This increased the chances for drinking water contamination.

To meet these challenges, engineers considered several pipeline designs. The first was a submarine pipeline. The plan seemed simple enough—just lay a pipe along the bed of Lake Mead to a point upstream of the sewage outlay. After closer analysis, however, engineers realized this option was considerably more complex than their initial assumptions. Lake Mead does not possess a typical lakebed. It is a reservoir built in extremely variable terrain. Under this plan, the pipeline would cross several ridges and require a number of concrete support structures, all of varying dimensions. What’s more, the area is geologically unstable. Dozens of faults crisscross the area, and the lakebed is composed of both soft sedimentary deposits and hard volcanic rock. A pipeline of this nature was fraught with risks and worked against the entire point of the project—to bring stability to Las Vegas’s water resource options. Simply put, too many things could go wrong with an underground pipeline. As a result, the SNWA board rejected this preliminary option.

A second alternative was to anchor a pump to a barge on the surface of Lake Mead. This provided the advantage of being able to move the pump as environmental conditions changed, but this option had significant shortcomings as well. SNWA designers worried over how to provide the power that would be needed to lift water from Lake Mead and send it to the Authority’s treatment plants on shore. This would have required either electrical or combustible power, both of which were problematic. Officials were reticent to run electrical cables through the lake to the barge or stockpiling gasoline on the structure to keep the pumps running. The National Parks Service also had concerns about a semi-permanent structure being placed on the surface of Lake Mead. The lake is, after all, a unit in the National Park System. Additionally, a barge required a lake. The Authority’s planners were expecting a contingency in which Lake Mead disappeared. Lake Mead very well may recede to the point at which it is replaced by the Colorado River. A barge simply would not work on a flowing river.

Courtesy of SNWA

The only viable option from the Board’s perspective, then, was to tunnel underneath the lakebed to a point upstream of the sewage outflow. This was the only option that guaranteed access to a clean and reliable water source, and one that could also withstand the challenges of Lake Mead’s underwater topography. In short, it was the most reliable plan available to the SNWA to deliver water to the metropolitan area in an increasingly dry era. Unfortunately, this reliability came at a price—the tunnel option was the most complex, dangerous, and expensive, estimated to cost over 800 million dollars.[5] Despite the challenges, it was the best hope the SNWA had; in 2005, the Board endorsed the underground pipeline plan and voted to begin construction.[6]

Over the next decade, construction crews labored to excavate millions of tons of dirt and rock from beneath Lake Mead. Doing much of the work was a six hundred foot long boring device that inched forward thirty-five feet per day.[7] While work progressed underground, crews simultaneously built and installed the intake structure itself, three miles offshore. In late 2014, the tunneling crew intersected the intake structure, and workers began making the final adjustments to bring the pipeline into operation.

In addition to the financial cost, there was also a human toll. In 2011, a jet of pressurized water dislodged a section of the tunnel, which struck and killed Thomas Turner, a forty four year old father of two.[8] His death stands as a stark reminder of the difficulties the SNWA faced during construction and of the challenges of maintaining a metropolitan population of two million people in a desert environment.

In 2015, approximately twenty-five million people in seven states and two nations depended on the Colorado River, taxing both the legal and physical infrastructures that managed thousands of competing interests. Las Vegas figures prominently in media accounts covering environmental challenges in the Colorado River Basin. Invariably, reporters utilize the Bellagio fountains as a symbol of the hubris of attempting to live in the desert and the impending environmental catastrophe.[9] Las Vegas assumes the role of the canary in a coal mine over whether life in the desert is ultimately sustainable.

Courtesy of SNWA

While there may be some truth this assertion, it is highly simplistic. Most media treatments of water and Las Vegas do not fully recognize the level to which the Law of the River influences political, economic, and social trends in the Colorado Basin. Nor do they examine how twenty-first environmental trends are rendering the Law of the River obsolete. The SNWA has had to address a legally imposed shortage since its inception and has radically altered the manner in which Las Vegas residents use water. Colorado River users in other states have thus far had a much greater amount of water at their disposal and are only now being forced to address the challenges the SNWA faced the day it was created. Unless commentators, scholars, and politicians study the economic uses of water within the Basin and how the legal proscription against interstate water transfers uniquely penalizes Nevada, future negotiations over Colorado River water will lead nowhere.

The enormous scale of the third intake belies a basic reality about Las Vegas water policy. Even though the SNWA continues to build its largest capital works project to date, and even though the most severe drought in centuries persists, the Law of the River is still the most consequential factor dictating Las Vegas’s access to water. Long before the lake dwindles to the point at which it makes the engineering features of the third intake necessary, the Secretary of the Interior will impose a mandatory shortage upon the states of Arizona and Nevada. In 2007, delegates from Nevada, Arizona, and California agreed that Nevada and Arizona would accept limitations to their annual Colorado River allocations should lake levels continue to drop. California agreed to limit its consumption to 4.4 million acre-feet, its legal allotment. Previously the Golden state had been consuming an average of 5.1 million acre-feet. So, in a sense it was accepting a limitation on its water supply. Arizona and Nevada, on the other hand, will see their allocations decreased below their legal entitlements.

When Lake Mead drops to elevation 1,075’, the Secretary will withhold 13,000 acre-feet from Nevada’s normal allotment. The next round of cuts will occur when the lake reaches 1,050’. At that point, Nevada loses an additional 4,000 acre-feet of water.[10] Las Vegas’s water situation bears repeating, especially given the amount of coverage about the drought: potential water shortages in southern Nevada are entirely the result of legal stipulations.

Even though precipitation has decreased throughout the Colorado River Basin, there are still a number of ways to increase efficiency and send water to the urban areas that are now facing shortages. One method a number of state and local governments have already tried is to pay farmers to fallow fields and free up agricultural water for use elsewhere. In Southern California, this has had a significant effect, transferring tens of thousands of acre-feet per year from Imperial Valley farmers to coastal metropolitan areas. While this has proven beneficial to many in Southern California, this option does nothing for Nevada. The Law of the River prevents interstate transfers of Colorado River water. Las Vegas has no option to utilize water previously allocated to agriculture. None of the state’s Colorado River allocation was designated for agricultural use. As such, there is no water to transfer. And, as chapter four showed us, despite years of attempts, the other Colorado River Basin states have prevented Nevada from changing the Law of the River to allow interstate water transfers.

There is no doubt that climate change presents a major challenge to the states sharing the Colorado River. However, when considering these challenges one must first understand where the vast majority of Colorado River water is used. Approximately eighty-five percent of the Colorado’s water presently goes to agriculture. And much of this amount is used to irrigate alfalfa, a crop not for human consumption, but for livestock. According to the Pacific Institute, “ninety percent of pasture and cropland in the 256,000-mile Colorado River Basin requires irrigation, with about sixty percent of the irrigated acreage devoted to pasture, alfalfa, and other forage crops used to feed cattle and horses. These forage crops consume about five million acre-feet of Colorado River water per year, equivalent to a third of the river’s annual flow.”[11] There’s no question that more suitable areas farther east exist for raising cattle. Much of the nation’s supply of beef comes from places like Kansas, Texas, and Florida, all of which possess greater amounts of annual rainfall than the states in the Colorado River Basin.[12]

Agriculture in the Imperial Valley
Agriculture in the Imperial Valley

After agricultural interests take their legal entitlement from the Colorado, the Basin’s urban areas then divide the remaining fifteen percent. This urban population is substantial; ten of the nation’s fifty largest cities—over ten million urbanites—rely on the Colorado River for all or part of their water supply. This total does not include the hundreds of small to medium sized suburban enclaves also dependent on the Colorado.

Urban areas form the basis for the Colorado River Basin’s economy, and dwarf agriculture’s economic contribution. In 2011, the Imperial Valley, the most valuable agricultural area to use Colorado River water, generated just under two billion dollars in agricultural output.[13] While this amount may sound substantial, it pales in comparison to the economies of the coastal cities to the west. During the same period, the Los Angeles-Long Beach-Santa Ana standard metropolitan statistical area generated nearly 750 billion dollars.[14] In fairness, Los Angeles does have a number of water sources it utilizes in addition to the Colorado River: the Owens and Los Angeles Rivers, and the Central California Aqueduct. However, Las Vegas, like the Imperial Valley, uses only Colorado River water, and the southern Nevada metropolis generated over ninety billion dollars during the same period.[15]

Furthermore, western American agriculture receives government-subsidized water. As Climate Scientist James Powell points out, “Imperial Valley farmers recently paid less than fifteen dollars per acre-foot, one twentieth the price of water in nearby San Diego.”[16] It should be noted, both Imperial Valley and San Diego rely on Colorado River water. Urban taxpayers are subsidizing water for farmers to grow crops that are either unneeded or grown more efficiently outside the Colorado River Basin. And while some supporters argue that these farms are growing the crops that feed the cities of the basin, this is only partially true, as significant portions of the Colorado River Basin’s agricultural production is exported to destinations around the globe.[17] In 2012, farmers in the Colorado River Basin exported the equivalent of over 150,000 acre-feet of water in hay alone.[18] This is half the amount of Las Vegas’s Colorado River allotment, an amount large enough to support nearly one million people.

The disparate economic relationship between rural areas and urban has existed within the Colorado River Basin for decades. However, in the twenty-first century, drought and climate change further complicated this tension. As the drought continues, the contrast between Colorado River water users that generate money and those that do not will become increasingly stark. As the relief between these competing demographics increases, political pressure will likely force a change. Given the increasing number of urban voters and persistent drought, lawmakers will inevitably be forced to shift water to the region’s cities. Likely, there will be a difficult political process in which state governments appropriate agricultural water rights (in a fashion similar to imminent domain seizures) for distribution to the region’s urban areas. This process is well underway in Arizona, California, and Colorado, all of which have seen transfers from agricultural to urban interests. However, in all these states, the transfers have thus far been temporary. Future transfers may be permanent. Regardless, these precedents suggest that the process will continue throughout the region, therefore making it unlikely that conditions in Las Vegas will reach crisis levels.

map basinAs the process of water redistribution in the Colorado River Basin progresses, the example of the SNWA can serve as a guide. The Las Vegas metro-area’s water agencies worked at cross-purposes for several decades. Their zeal to protect their water created so much tension among local politicians that commentators saw little reason for optimism. In the mid-1980s very few people would have predicted a time in which the region’s politicians and water managers would work together for the common good of the metropolitan area. But work together they did. As a result of environmental and legal pressure, these officials relinquished a significant amount of their autonomy and joined the SNWA. While the number of competing political interests in the Colorado River Basin is substantially greater than that of 1989 Las Vegas, the history of the SNWA can at least serve as a starting point. If nothing else, the SNWA example demonstrates that conflict is not the only option when negotiating for water.

Unless a fundamental change occurs to the Law of the River, however, the Las Vegas as a model scenario would be truly ironic. If, in the coming decades, state governments initiate a plan of agricultural to urban transfers, it would mark one the most significant political developments in the history of the Colorado River Basin. However, in order to be of benefit to southern Nevada, the Law of the River itself will need serious revision. As long as it prevents interstate transfers of water, it will not matter that other states shift agricultural water to their cities. This may help Denver and Salt Lake City, but it will do nothing for the Las Vegas metro-area. Unlike the other states, which have multiple users of Colorado River water, the SNWA possesses rights to the entirety of Nevada’s allocation. As a result, there is no agricultural water within Nevada to transfer to Las Vegas.

As part of the regional water rights shakeup, it would be reasonable then to propose the creation of a Colorado River Basin Water Authority, comprised of member agencies. Again, the SNWA model serves as a guide. One of the main reasons for the SNWA’s success was that under the Authority’s cooperative agreement, smaller agencies had the same political standing as the larger ones. This simple administrative feature created a shared destiny for the water agencies of the Las Vegas metro-area. They were all in their struggle together. It is time for the SNWA model to expand to the scale of the Colorado River Basin. Water shortage threatens each of the Colorado River Basin states, much like it did each of the Las Vegas metro area water agencies in 1989. It is reasonable to suggest that these seven states begin “thinking like a river basin” and accept their shared destiny and create an administrative agency that can manage the Colorado River as a single unit.[19]

It is necessary, then, to throw out the Law of the River as it is now written. Thus far, the various agreements among states have been a series of half measures. None of them fundamentally alter the structure of the Law of the River. Even with the 2007 sharing agreements in place, agriculture retains a favored position within the Colorado River Basin, courtesy of the Law of the River. A new Law of the River is needed if the urban centers of the Colorado River Basin states are to survive. These cities have proven to be the economic powerhouses of the Colorado River Basin, a status they will need to maintain if the regional prosperity is to continue. Agriculture, on the other hand, has been in decline for decades. It is now time to accept this reality and adopt a legal regime to suit. This trend is well underway, in no small part because of the efforts of the SNWA.


An environmental and public historian, Christian Harrison is currently working on a history of the Law of the Colorado River and of water use in Las Vegas. He is a life-long resident of the Silver State, and teaches American History at the University of Nevada, Las Vegas and the College of Southern Nevada when not out exploring the Mojave with his children.

[1] Tim P. Barnett and David W. Pierce, “When will Lake Mead go dry?” Water Resources Research 44 (2008): W03201, doi:10.1029/2007WR006704. deBuys, William (2011-10-28). A Great Aridness: Climate Change and the Future of the American Southwest. Oxford University Press. Kindle Edition.

[2] Matt Jenkins, “The Water Czar who Reshaped Colorado River Politics,” High Country News, March 2, 2015.

[3] Conor Shine, “Lake Mead’s water levels expected to drop further to unseen levels,” Las Vegas Sun, April 24, 2015.

[4] Phoebe Sweet, “Lake’s ghost town seen as a warning,” Las Vegas Sun, 12 March 2008; James L. Powell, Dead Pool: Lake Powell, Global Warming, and the Future of Water in the West (Berkeley: University of California Press, 2008), 183.

[5] Bronson Mack, Southern Nevada Water Authority Public Relations Officer, Power Point Presentation, Discovery Channel, October 23, 2013, author’s possession.

[6] Ibid.

[7] Kalee Thompson, “Last Straw: How the Fortunes of Las Vegas Will Rise or Fall With Lake Mead,” Popular Science Magazine, June 11, 2014, accessed April 26, 2015,

[8] Henry Brean and Laura Myers, “After seven years of digging, Vegas reaches its last straw,” Las Vegas Review-Journal, December 9, 2014.

[9] Alisa Barba, “Struggling over water: A series overview,” National Public Radio, 11 June 2007, available from, Internet, accessed 21 August 2013.

[10] Southern Nevada Water Authority, Lower Basin Tour Binder, Las Vegas, Southern Nevada Water Authority, 2008, author’s collection.

[11] Pacific Institute, “Water to Supply the Land: Irrigated Agriculture in the Colorado River Basin,” 9 May 2013, Internet, available from, accessed 18 August 2013.

[12] James L. Powell, Dead Pool: Lake Powell, Global Warming, and the Future of Water in the West (Berkeley: University of California Press, 2008), 242-243; Powell draws a similar conclusion in his book. He calls into question the immutability of the Law of the River and argues that it was a politically created set of laws, and that it can, and must, be undone politically.

[13] California Agricultural Statistics Review, 2012-2013, Internet, available from, accessed 21 August 2013.

[14] Bureau of Economic Analysis, available from, Internet, accessed 18 August 2013.

[15] Bureau of Economic Analysis, available from, Internet, accessed 18 August 2013; Hal Rothman, “It’s time for a new law of the river” in River Basins of the American West: a High Country News Reader. ed. Char Miller (Corvallis: Oregon State University Press, 2009); Charles Wilkinson, Crossing the Next Meridian: Land, Water, and the Future of the West (Washington, D.C.: Island Press, 1992); both authors call for a radical reorientation of natural resource policy in the American West. Rothman and Wilkinson point out that environmental and demographic realities are significantly different that when most natural resource policies were established. It is therefore time to craft policy to fit this new reality.

[16] James Lawrence Powell, Dead Pool: Lake Powell, Global Warming, and the Future of Water in the West (Berkeley, University of California Press, 2008), 83.

[17] Imperial Valley’s own website describes how the area exports produce throughout the nation. Imperial Valley Agriculture, available from, Internet, accessed 22 August 2013.

[18] Ben Jarvey, “Exporting the Colorado River to Asia, Through Hay,” National Geographic Magazine, January 23, 2014.

[19] Center for Natural Resources & Environmental Policy, The University of Montana, “Thinking Like a River Basin: Leaders’ Perspectives on Options and Opportunities in Colorado River Management,” Internet, available from, accessed 2 November 2013; It is from this report that I borrowed the phrase “thinking like a river basin.”


1 comment on “The Final Intake: Las Vegas’s Search for Water Security

  1. Pingback: Las Vegas’s Search for Water Security | Northwest Iowa Center for Regional Studies

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