Increasing aridification across the West has become a point of national discourse and regional contention. The current drought contingency plans on the Colorado River, crafted between 2007 and 2019, are set to expire in 2026. The states in the basin are facing off with competing proposals to address a shrinking supply of water, while tribes and Mexico press for recognition of their claims in the negotiations. Texas, New Mexico, Colorado, and the federal government are arguing in front of the U.S. Supreme Court over how the waters of the Rio Grande can be split and how fundamental aspects of federalism impact the dispute.
These conflicts, and many more at the local level, are being driven by what scientists have dubbed a “megadrought,” the driest 20 years on a paleo-reconstructed record going back to 800 CE. Flows in the Colorado River basin have fallen 20% over that timeframe. Even winters with abundant snowpack have failed to bolster reservoir levels as drier soils and air soak up the potential excess. U.S. Geological Survey (USGS) scientists Chris Milly and Krista Dunne used advanced computer modeling to predict future supply scenarios based on changes to both temperature and precipitation patterns under a range of continued greenhouse gas emissions. They concluded that each additional degree Celsius in warming would result in a 9.3% reduction in flows. In high-emissions scenarios pairing projected temperature and precipitation pattern change, flows in the basin could increase 3% or fall by 40% compared to historical values. P.C.D. Milly & K.A. Dunne, Colorado River Flow Dwindles as Warming-Driven Loss of Reflective Snow Energizes Evaporation, 367 Science 1252 (2020).
This growing scarcity has brought more scrutiny to how we use water and whether that use meets our economic, cultural, and moral expectations in a dry land. As a result, some communities are eliminating the irrigation or installation of nonfunctional turf. Different definitions exist from state to state and between neighboring municipalities, but if you only step on grass to cut it, that’s nonfunctional turf. This does not tend to include residential lawns, golf courses, or public parks; instead, the definition is aimed at turf planted alongside highway exits and shopping mall parking lots and in street medians. This nonfunctional turf accounts for about a third of all irrigated grass in the desert metropolis of Las Vegas, totaling some six square miles.
Stopping the irrigation of climactically inappropriate ornamental grass in the West presents an attainable pathway to address the region’s water woes. Doing so may only represent a small fraction of needed conservation in the region, but it is part of the larger picture of bringing our water use and water supply in balance.
The progenitor of nonfunctional turf bans was municipal conservation efforts aimed at reducing outdoor water use on residential lawns. These programs date back to at least the 1980s, when Denver Water introduced its xeriscaping program. The term “xeriscape” combines the Greek word for dry—xeros—with the word “landscape” and encourages landowners to plant their spaces with plants adapted to the semi-arid conditions of the West. An unfortunate tendency of landowners to hear the word “zeroscape,” followed by a complete covering of lawn areas with rock, has led other agencies to use other terms like “water-wise” landscaping. Whatever the term, the goal remains to reduce outdoor water use in urban areas for lawn irrigation, which can account for 50% of residential water used in Colorado and up to 70% of residential water use in Arizona. R. Waskom & M. Neibauer, Water Conservation in and Around the Home (2014); Ariz. Dep’t of Water Res., Conservation: Landscaping—Residential & Professional (2024).
Municipalities have a long history of providing voluntary incentive programs to remove water-intensive lawns, typically by paying landowners per foot of turf removed. States followed behind by offering their own support to the effort, either through state-administered programs or by providing funding to existing and new local programs. Of the 17 western states bisected or west of the 100th meridian, 11 (Arizona, California, Colorado, Nebraska, Nevada, Oklahoma, South Dakota, Texas, Utah, Washington, and Wyoming) have some kind of program to incentivize landscape conservation, constituting the greatest common approach to landscape conservation between them. A smaller subset of six states (California, Colorado, Kansas, Texas, Utah, and Washington) require public entities to take landscape conservation measures, and eight (Arizona, California, Colorado, Nevada, Oregon, Texas, Utah, and Washington) explicitly limit the power of associations, like homeowner associations, to impede water-saving practices.
Some of these voluntary programs have been very successful. Incentives in the Las Vegas Valley have eliminated over 200 million square feet of turf over the last 20 years. But despite these successes, the growing water crisis in the West has pressed states further to either ban the irrigation of nonfunctional turf or to forbid the installation of it altogether.
The Southern Nevada Water Authority (SNWA), which serves the communities of the Las Vegas Valley, is in a unique position to peer over the bathtub ring into the literal and figurative abyss of Lake Mead. The reservoir supplies roughly 90% of the water to Clark County and is completely reliant on Colorado River flows. Throughout the 2000s and 2010s, physical conditions forced the SNWA to install new intakes into the reservoir to chase falling water levels. In 2021, the SNWA was forced to reckon with mandatory delivery reductions from the lake under the Law of the River, that group of compacts, statutes, and guidelines that divvy out the waters of the Colorado. These cuts and continued projections for reduced flows spurred the SNWA and the Nevada Legislature to pass Assembly Bill 356 in 2021. The law forbids irrigating and, in some cases, requires removing nonfunctional turf in the SNWA area with Colorado River water. Simultaneously, the SNWA adopted its Resolution Prohibiting the Installation of New Turfgrass and Spray Irrigation Systems Within the Service Area of SNWA’s Purveyor Members (2021) to prohibit installation of irrigated grass in new commercial and residential developments.
These two prohibitions are supported by the ongoing Water Smart Landscapes rebate program that was so successful in eliminating irrigated turf in the Las Vegas Valley in the first place. The program provides $3 per square foot of grass removed, and nonfunctional turf must be replaced with a canopy cover rather than simply being eliminated. According to SNWA staff, support for the ban was primed by longstanding conservation efforts and financial incentives to lessen the burden of compliance.
Responding to their own water supply problems, as well as threats from the Bureau of Reclamation to impose further unilateral cuts to Colorado River deliveries, California, Colorado, and New Mexico have begun to look at Nevada’s law as an example for their own bans on nonfunctional turf.
California’s ban began as Executive Order N-7-22 in March 2022, signed by Governor Gavin Newsom in response to ongoing drought conditions across the state. The order directed the Department of Water Resources to consider an emergency regulation banning irrigation of nonfunctional turf with potable water, which it did in May 2022 and subsequently readopted in 2023. State Water Resources Control Board Resolution No. 2023-0014-EXEC (2023). The California legislature quickly moved to make these restrictions permanent in Assembly Bill 1572. Committee comments cited conditions on the Colorado River and across the state as motivators for the ban, highlighting the potential to save 400,000 acre-feet of water per year through turf conservation. The comments also highlighted the similarity of the language in the bill to that used in Nevada. While water systems in California will need to change their regulations or ordinances to reflect this prohibition by 2027, there is a possibility that the emergency regulations will be renewed each year until that date.
Colorado has a long history of local water conservation programs. As of 2023, 22 local programs have targeted nonfunctional turf, but only 10 of them have been accompanied by restrictions on new turf installation. During the 2022 legislative session, the Colorado legislature passed House Bill 22-1151 to fund a statewide turf replacement plan. In 2024, the legislature followed on this success by passing Senate Bill 24-005, which prohibits the future installation of nonfunctional turf by private or state entities but does not require the removal of existing nonfunctional turf or apply to residential properties. Both bills passed with bipartisan support across urban and rural areas.
Colorado’s state programs and legislation were informed by a concerted effort of the Colorado Water Conservation Board (CWCB) to understand the future water needs of the state. In 2015, the CWCB released the first Colorado Water Plan, a collaborative effort across the state and across industries to balance water conservation and development. The 2019 technical update and the 2023 Water Plan project a potential supply gap of 230,000 to 740,000 acre-feet of water per year by 2050. This quantified potential shortfall across the state, as well as water providers’ own projections, has broadened public and institutional support for more aggressive and mandatory conservation measures.
In 2023, New Mexico legislators unsuccessfully introduced House Bill 352, which would have banned the installation of nonfunctional turf, prohibited the use of potable water to irrigate nonfunctional turf, and required that nonfunctional turf be replaced with drought-resistant landscaping. The bill did not, however, come with the kind of statewide funding or administrative support present in Nevada, California, and Colorado. Representative Cande Spence Ezzell of Roswell opposed the bill, telling KRQE News, “You’re putting the burden on local communities that they have to police areas of their particular district so that they are in compliance with this.” Natalie Wadas, Push to Ban Grass Fails to Take Root in Roundhouse, KRQE (Feb. 14, 2023). The bill died in the House Agriculture Committee in a 4-4 vote not to pass.
As we look to the future, Western climate experts like Jonathan Overpeck, Bradley Udall, and Tanya Petach believe that flash droughts, extreme dry spells, and interannual droughts will become part of the new, more arid normal. Specific supply-gap projections, and the real possibility of water delivery reductions, developed the political will and social support necessary to pass nonfunctional turf bans in Nevada, California, and Colorado. However, each of these states also has histories of robust local conservation programs and state programs preceding legislation to prevent the installation or watering of nonfunctional turf. New Mexico’s relatively slim portfolio of local programs and lack of a statewide program to support mandatory local efforts may help to explain the failure of House Bill 352 to advance out of committee.
As mandatory landscape conservation efforts increase across the region, the presence or absence of these factors may prove crucial to successful legislation. Other states are also likely to shape their prohibitions based on the physical and political realities of their states. The geographically bounded prohibition of Nevada’s ban may be a useful template for policy makers who need to address disparate water issues across and within states. This approach could be beneficial in the Pacific Northwest and Great Plains states that have different hydrologic realities across their geography. Requirements to comply with particular water-sharing compacts with neighboring states also may provide an impetus for bans of limited area. An aggressive legislature also could combine the elements of the existing bans to produce one that is statewide, requires nonfunctional turf’s removal, and prohibits future installation. Only time, and drought, will tell.
The CWCB (Colorado) is catching up to the state’s legislation to determine how much water will be saved through its investment in turf replacement. Meanwhile, exceptions and calculation errors are undercutting the initial savings estimates in the Las Vegas Valley. ProPublica has estimated that only about a third of the initial anticipated benefits can be achieved. Nat Lash et al., Las Vegas Needs to Save Water. It Won’t Find It in Lawns, ProPublica (June 7, 2023). Even if these programs were perfect, however, they could still only play a small part in the overall water supply challenge across the region. It is a well-worn axiom that 80% of Western water is used by agriculture and that removing every city in the Colorado River Basin would not correct our current supply-use imbalance. Even so, there are fiscal, social, and moral reasons to contemplate the end of nonfunctional turf in the West.
Colorado Springs and Nevada’s SNWA pay $10,000 and $17,000 in one-time costs respectively to conserve an acre-foot of water in their service area. This may end up being a steal as water prices increase; a coveted acre-foot in northern Colorado recently broke records when it sold for $85,000. It’s not clear that SNWA would be able to acquire a significant supply of additional water at any price. In an increasingly arid climate, conservation is likely to become the cheaper option. Water providers also can realize savings from the amount of energy necessary to treat and transport water used to irrigate nonfunctional turf.
Physical and fiscal savings will only be realized, however, if the water is saved to hedge against future drought or allowed to enrich the built natural environments. If water savings are instead used to continue urban growth, we will likely fall victim to a watery Jevon’s Paradox, whereby those savings result in greater growth and greater water demands. The inability to stop supplying water to new homes and businesses will lead to demand hardening, the inability to reduce demand in times of scarcity, and make our cities less resilient. While lack of available water has stopped growth in cities like Fountain, Colorado, discussions on limiting growth have been taboo—a position that seems to be changing. Prohibitions on growth are bound up in equally important legal and moral questions, but they are worth asking. Irrigating a median may not be a good use of water in the West—but value judgments will only become more difficult from there.
This is not to say that water savings don’t have beneficial urban uses. The goal of turf removal is not barren urban landscapes made of impermeable surfaces. Instead, the goal is to produce climatically appropriate landscaping that can be used to address multiple environmental and societal issues, including the heat island effect, lack of green spaces, and lack of habitat for native fauna. Flagstaff and Avondale, Arizona, have great examples of conservation programs that require replacement of grass with canopy cover paired with a limitation on rock and hardscaping. But cities could take the next step in greening their urban spaces with water savings.
Cities across the West display high disparities of canopy cover and available green space across neighborhoods of different wealth and racial/ethnic compositions. In Phoenix, the widest gap in canopy cover between a neighborhood of color and a white neighborhood is 19%. Jake Frederico, In Low-Income Phoenix Neighborhoods, the Lack of Shade Trees Is a Question of Equity, azcentral (May 25, 2023). A robust body of science has established that canopy cover and green spaces are positively correlated with mental and physical well-being, life expectancy, and safe urban temperatures. Water savings and new streams of funding should be used deliberately to make our urban areas better places to live, not just close the urban supply-growth gap.
Agriculture and industry will also need to contribute to water savings across the West. The question is how all sectors, and how we as a society, face scarcity together. To invokeWendell Berry, we need to solve for the patterns within aridity. Our solutions should improve balances, symmetries, and harmonies. Each solution should solve more than one problem, and we must avoid enriching one person or community through the distress or impoverishment of another. Conserving water used on nonfunctional turf can make our urban areas more resilient while helping to maintain vibrant agricultural communities.
