CAMBRIDGE, Mass. – The Consortium for Scenario Planning, an initiative of the Lincoln Institute of Land Policy, has announced the selection of four projects that will work to advance the state of scenario planning, a practice by which communities and regions can make better decisions about the future by incorporating data and diverse stakeholder input.

Four teams, representing the Eastgate Regional Council of Governments, GreaterPlaces, the National Center for Smart Growth, and the University of Illinois at Urbana Champaign’s Department of Urban and Regional Planning, will receive a combined $35,000 to apply scenario planning to challenges ranging from population decline to climate change.

Scenario planning is a decision making process that helps governments and citizens consider alternative futures by comparing the outcomes of various policies, and by visualizing data such as demographic and economic indicators, and different land use and transportation patterns. Founded in 2017, the Consortium works at the forefront of this practice and is focused on benefiting urban and rural professionals, such as those working in planning, development, or city operations, to expand capacity in and understanding of scenario planning processes and software tools.

“The Consortium works to make scenario planning accessible to those new to the practice while continuing to support experienced professionals, and we congratulate the winners on undertaking projects that will advance this dual mission,” said Amy Cotter, Associate Director of Urban Programs at the Lincoln Institute. “These projects demonstrate a clear commitment to improving the state of scenario planning, and they have the potential to create new approaches for better integrating uncertainty, flexibility, and resiliency into planning.”

The projects were selected from proposals submitted in response to a Request for Proposals for Impactful Projects, which was first announced at the Consortium’s annual conference in September. The Consortium chose the four projects based on their potential impact, feasibility, and connection to the Consortium’s other initiatives. The RFP also asked that projects address one of the Consortium’s key areas of focus, which include capacity building and peer exchange, software interoperability, and scenario planning process design.

With the award money, Sara Daugherty, Economic Development Program Manager for the Youngstown, Ohio- Eastgate Regional Council of Governments, will research how to best adapt scenario planning tools to address population decline. She will develop and test software to support different strategies for addressing this challenge.

Lisa Nisenson, co-founder of GreaterPlaces, an urban design consulting firm in Arlington, Virginia, will create example ‘scopes of work’ for multiple types of typical scenario planning projects, so that organizations in need of a draft scope of work for a procurement effort won’t need to start from scratch. 

Uri Avin, Planning and Design Director at the National Center for Smart Growth, will pilot several scenario planning workshops. As part of this effort, the Center will match organizations in need of particular scenario planning services with subject matter experts who can offer the type of workshop required.

Arnab Chakraborty, Professor of Urban and Regional Planning and Associate Dean at the University of Illinois at Urbana Champaign, will explore the precise impacts of scenarios on a range of past planning efforts and resulting decisions. By gaining such insights, high impact aspects of scenario planning can be further integrated into the Consortium’s capacity building initiatives.

The Lincoln Institute of Land Policy seeks to improve quality of life through the effective use, taxation, and stewardship of land. A nonprofit private operating foundation whose origins date to 1946, the Lincoln Institute researches and recommends creative approaches to land as a solution to economic, social, and environmental challenges. Through education, training, publications, and events, we integrate theory and practice to inform public policy decisions worldwide.

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The desert city of Tucson, Arizona, has an average annual rainfall of just 12 inches. But when the rain comes, it often comes in the form of torrential downpours, causing damaging floods across the city. This is a perhaps ironic challenge for Tucson and the broader Pima County area in which it is situated, given that it’s part of a much larger region working to ensure that there is—and will continue to be—enough water to go around in a time of unrelenting drought.

Both of these distinct water-management challenges—too dry and too wet—can be addressed by thoughtful land use and infrastructure decisions. Of course, when making such decisions, it helps to have precise mapping data on hand. That’s why Pima County officials are working with the Lincoln Institute’s Babbitt Center for Land and Water Policy and other key partners to pilot the use of some of the most cutting-edge mapping and data analysis tools on the market.

For the Babbitt Center—founded in 2017 with the mission of providing land-use research, education, and innovation to communities throughout the Colorado River Basin—the partnership represents one early step in exploring how such technology can be used to help integrate water and land use management across the region.

The technology itself originated across the country, at the Conservation Innovation Center (CIC) of Maryland’s Chesapeake Conservancy, a key player in cleaning up the notoriously pollution-addled Chesapeake Bay. To oversimplify a bit: CIC has designed image analysis algorithms that provide distinctly more granular image data of the earth’s surface. The technology has enabled a shift from a resolution that made it possible to observe and classify land in 30-meter-square chunks to a resolution that makes that possible at one square meter.

The details are of course a little more complicated, explains Jeffrey Allenby, the Conservancy’s director of conservation technology. Allenby says the new technology addresses an historic challenge: the compromise between resolution and cost of image collection. Until relatively recently, you could get 30-meter data collected via satellite every couple of weeks or even days. Or you could get more granular data collected via airplane—but at such a high cost that it was only worth doing every few years at most, which meant it was less timely.

What’s changing, says Allenby, is both the camera technology and the nature of the satellites used to deploy it. Instead of launching a super-expensive satellite built to last for decades, newer companies the CIC works with—Allenby mentions Planet Labs and DigitalGlobe—are using different approaches. “Smaller, replaceable” satellites, meant to last just a couple of years before they burn off in the atmosphere, can be equipped with the latest camera technology. Deployed in a kind of network, they offer coverage of most of the planet, producing new image data almost constantly.

Technology companies developed this business model to respond to commercial and investor demand for the most recent information available; tracking the number of cars in big-box store parking lots can, in theory, be a valuable economic indicator. Land use planners don’t need images quite that close to real time. But Allenby says the CIC began asking the tech companies, “What are you doing with the imagery that’s two weeks old?” It’s less expensive to acquire, but far better than what was previously available. The resulting images are interpreted by computers that classify them by type: irrigated land, bedrock, grassland, and so on. Doing that at a 30-square-meter level required a lot of compromise and imprecision; the one-meter-level is a different story.

The goal is to “model how water moves across a landscape,” as Allenby puts it, by combining the data with other resources, most notably LIDAR (Light Detection and Ranging) elevation data. Those are the “flour and eggs” of land use data projects, supplemented with other ingredients like reduction efficiencies or load rates from different land cover, depending on the project, Allenby says: “We’re building new recipes.” For Chesapeake Bay, those recipes are meant to help manage water quality. If you can determine where water is concentrating and, say, taking on nitrogen, you can deduce the most cost-effective spot to plant trees or place a riparian buffer to reduce that nitrogen load. (See “Precision Conservation,” October 2016 Land Lines.)

In the Colorado River Basin, the most urgent current water-management challenges are about quantity. Since water policy is largely hashed out at the local level despite the underlying land use issues having implications across multiple states, the Babbitt Center serves as a resource across a broad region. There’s currently a “heightened awareness” of water management among municipal and county policy makers, says Paula Randolph, the Babbitt Center’s associate director. “People are wanting to think about these issues and realizing they don’t have enough information.”

That brings us back to Pima County. Although it lies outside the basin, it boasts two features that make it a good place to evaluate how the uses of precision mapping data might be applied in the West: Basin-like geography and proactive municipal leaders. When the manager of technology for the Pima Association of Governments saw Allenby speak about the benefits of his work in the East, he contacted the CIC to discuss possibilities for the West. A year into the resulting project, several partners are on board, the group is mapping a 3,800-square-mile area, and the open-source data lives on the Pima Regional Flood Control District website, where others throughout the county are able to access and use it.

Broadly, this process has taken some effort, Randolph notes. Satellite data gathered in the West has different contours than the East Coast imagery that Chesapeake’s sophisticated software was used to, and that has required some adjustment—“teaching” the software the difference between a Southwestern rock roof and a front yard that both look (to the machine) like dirt. “We need human partners to fix that,” she says. “We strive for management-quality decision-making data.”

Even as such refinements continue, there are already some early results in Pima County. Clearer and more precise data about land cover is helping to identify areas that need flood mitigation. It has also been useful to identify “hot spots” where dangerous heat-island effects can occur, offering guidance for mitigation actions like adding shade trees. These maps provide a visual showcase about water flow and land use more efficiently than a field worker could.

Both Allenby and Randolph stress that this partnership is still in the early phases of exploring the potential uses and impacts of high-resolution map data. Randolph points out that while the Babbitt Center is working on this and another pilot project in the Denver area, the hope is that the results will contribute to a global conversation around water-management experimentation.

And Allenby suggests that the “recipes” being devised by technologists, policy makers, and planners will ideally lead to a shift in more accurately evaluating the efficiency and impact of various land use projects. This, he hopes, will lead to the most important outcome of all: “Making better decisions.” 

The Lincoln Institute has provided occasional financial support to the CIC for map- and data-related projects.

Rob Walker (robwalker.net) is a columnist for the Sunday Business section of The New York Times.

Image: High-resolution land cover data offers a closer look at Tucson, Arizona. Credit: Chesapeake Conservancy.

Agriculture was the main driver of development along the Colorado River. According to a recent report from the U.S. Geological Survey, 85 percent of water withdrawals went toward irrigation between 1985 and 2010 (Maupin 2018). The fields around Yuma, Arizona, and the Imperial and Palo Verde valleys of California consume more than 4 million acre-feet of Colorado River water annually, nearly a third of the river’s annual flows. But with population growth, water use has shifted to urban needs.

In Colorado, for example, 95 percent of water imported from the Colorado River headwaters through the Colorado-Big Thompson (CBT) project was once used for agriculture; now, that number is closer to 50 percent. As another example of the complexity of systems in the Colorado River Basin, CBT water is divided into units which can be bought and sold. The amount of water in a unit varies year to year depending on the total amount of water available; when CBT is at full capacity, a unit is one acre-foot. Agricultural users owned 85 percent of the units when trading began in the late 1950s, but currently own less than one-third of available units. Municipalities own the balance, but often lease the water to farms until it’s needed. The current price for a CBT unit is close to $30,000.

Such water-sharing agreements are becoming more common in a system stretched too thin. Rotational fallowing, also known as lease-fallowing or alternative-transfer mechanisms, has played a role in shifting water from farms to cities. Farmers in the Palo Verde Valley struck a deal with the Metropolitan Water District of Southern California, which serves 19 million customers, to fallow between 7 and 35 percent of their land on a rotating basis. Metropolitan’s customers, in turn, get the water, which can be stored in Lake Mead. Similar deals, still underlined with tension but increasingly accepted, exist between Southern California municipalities and farmers in the Imperial Valley and between cities and farmers along Colorado’s Front Range urban corridor.

For their part, cities tend to tout conservation and development efforts they’ve made with water in mind. Many are encouraging density, reducing the water needed for landscaping; some have implemented turf-removal programs; and toilets, showers and other fixtures have become more efficient. Metropolitan Water District of Southern California chalked up a 36 percent per capita reduction in water use from 1985 to 2015, a time of several droughts, according to Planning magazine (Best 2018).

In Nevada, the population served by the Southern Nevada Water Authority has increased 41 percent since 2002, but the per capita consumption of Colorado River water fell 36 percent. The agency’s Colby Pellegrino, speaking at a September 2018 conference called “Risky Business on the Colorado River,” said conservation is the first, second, and third strategy for achieving reduced water consumption. “If you live in the Las Vegas Valley, where there is less than 4 inches of rainfall a year, and you have a median covered in turf, and the only person walking on that turf is the person pushing a lawn mower—that is a luxury our community cannot afford, if we want to continue to have the economy we have today,” she said.

Economy, culture, and values have been at the core of the basinwide debate about how to respond to the drought. No one sector or region can absorb the full burden of necessary reductions, and it’s clear that everyone must begin to think differently. Speaking at the “Risky Business” conference, Andy Mueller, general manager of the Colorado River Water Conservation District, put it this way: Instead of the intentional use of water, Colorado is now talking about the intentional non-use of water. As is everyone who lives and works in the Colorado River Basin.

This content is excerpted from the article “Hydraulic Empire” published December 14, 2018.

Allen Best writes about water, energy, and other topics from a base in metropolitan Denver, where 78 percent of his water comes from the Colorado River Basin.

Photograph: On a farm in Yuma, Arizona. Credit: Amy Martin, courtesy of American Rivers.

References

Arizona Daily Star. 1998. “Don’t Ignore Colorado Delta.” May 6, 1998.

Best, Allen. 2018. “Water Pressure: Smart Management Is Key to Making Sure Inland Cities Aren’t Left High and Dry in the Face of a Warming Climate.” Planning August/September: 40–45. https://www.planning.org/login/?next=/planning/2018/aug/waterpressure/.

Maupin, Molly A., Tamara Ivahnenko, and Breton Bruce. 2018. “Estimates of Water Use and Trends in the Colorado River Basin, Southwestern United States, 1985–2010.” Reston, Virginia: U.S. Geological Survey. https://pubs.er.usgs.gov/publication/sir20185049.

For six centuries, a people called the Hohokam inhabited central Arizona. Among their many accomplishments, they created a hydraulic empire of sorts, a spiderlike web of canals intended to deliver water from the Gila and Salt rivers—tributaries of the mighty Colorado—to their agricultural fields. Eventually, the Hohokam abandoned their fields and canals. To this day, the reason is uncertain, but historian Donald Worster once surmised that the productive but ill-fated tribe “suffered the political and environmental consequences of bigness” (Worster 1985).

Bigness. It’s the perfect word to describe not only the Colorado River Basin, but so much of the geography, history, culture, politics, and challenges associated with it.

In its sheer complexity, the Colorado stands out among the rivers of America, and probably the world. In this river basin of 244,000 square miles, one-twelfth the land mass of the continental United States, exist great diversities, places of oven-hot heat and icy vastness. All but 2,000 of those square miles lie in the United States. Just 10 percent of that land mass, mostly in an elevation band of 9,000 to 11,000 feet in the Rocky Mountains, produces 90 percent of the water in the system.

Hydraulic infrastructure abounds at almost every turn on the river’s 1,450-mile journey. The first diversions occur at its very headwaters in Rocky Mountain National Park, before the river can rightfully be called a creek. Fourteen dams have been erected on the Colorado River, and hundreds more on its tributaries. Hoover Dam, perhaps the best known, hulks a half-hour drive from Las Vegas. The U.S. Bureau of Reclamation (USBR) built it in the 1930s to hold back the river’s spring floods, creating a reservoir now known as Lake Mead. A second massive reservoir, Lake Powell, lies upstream 300 miles. It’s the result of Glen Canyon Dam, built in the 1960s with the goal of providing a means for the four Upper Basin states—Colorado, New Mexico, Utah, and Wyoming—to store the water they had agreed to deliver to the Lower Basin states of Arizona, California, and Nevada, and to Mexico.

At their fullest, the two reservoirs—which are the biggest in the country—can hold four years of flows of the Colorado River. A recent paper suggested that the two reservoirs could be considered one giant reservoir, bisected by a “glorious ditch” (CRRG 2018). That ditch is the Grand Canyon, which celebrates the one hundredth anniversary of its designation as a national park this year.

The dams, reservoirs, tunnels, and aqueducts of the Colorado deliver water to 40 million people in seven U.S. states—more than 1 in 10 Americans—and two Mexican states. The river’s water also nourishes more than 5.5 million acres of agricultural fields within and outside the river basin. Residents of Denver, Los Angeles, and other cities outside the basin rely on the river; crops in fields reaching almost to Nebraska benefit from transbasin exports and diversions.

The river provides a cultural and economic resource for 28 tribes within the basin. A $1.4 trillion economy hums along in and around the basin. This includes the snowmaking cannons at Vail and Aspen, the nightly water spectacle at the Bellagio in Las Vegas, and the aeronautics industry of Southern California. Up and down the river, more than 225 federal recreation sites draw visitors eager to try their luck at fishing, rafting, hiking, or just taking in the sights. This river and the lands around it loom large in the public imagination.

It’s a big, complicated, and now vulnerable hydraulic web. Entering the twenty-first century, the river was already a sponge fully squeezed, its water rarely making it to the Gulf of California.

Rapid population growth, rising temperatures, and declining river flows are putting pressure on the system, forcing river managers and users to devise creative, forward-looking plans that consider both water and land. The Lincoln Institute’s Babbitt Center for Land and Water Policy strongly encourages this approach. “We are trying to think more holistically by considering the management and planning of land and water resources together,” says Babbitt Center Program Manager Faith Sternlieb. “These are the foundations upon which water policy in the Colorado River Basin has been considered and crafted, and these are the roots we must nurture for a sustainable water future.” 

Taming the Colorado

The need to nurture roots has driven the development of the Colorado River Basin since the first people began farming there. The Hohokam, Mojave, and other tribes built canal systems of varying complexity to irrigate their fields. In the late 1800s, federal interest in tapping the river to boost agricultural production surged. By 1902, the U.S. Department of the Interior (DOI) had created what is now the Bureau of Reclamation. During the twentieth century, the Bureau became the prime builder, and funder, of agricultural water projects throughout the basin.

Work on the Laguna Diversion Dam, the first dam on the Colorado River, began in 1904, yielding water a few years later for fields near Yuma, Arizona. Yuma sits in the Mojave Desert, where Arizona, California, and Mexico come together. There, long, nearly frost-free growing seasons coupled with fertile soils and Colorado River water enable extraordinary productivity. Today, farmers in the Yuma area of Arizona and Imperial Valley of California proclaim that during winter they grow 80 to 90 percent of the greens and other vegetables in the United States and Canada. This area, declares Arizona’s Yuma County Agriculture Water Coalition, is to U.S. agriculture what Silicon Valley is to electronics and what Detroit was to automobiles (YCAWC 2015).

All told, irrigation accounted for 85 percent of total water withdrawals in the basin between 1985–2010 (Maupin 2018). Today, agriculture still accounts for 75 to 80 percent of total water withdrawals. This supports row crops such as corn and the perennial crop of alfalfa, which is grown from Wyoming to Mexico. Much of the crops go to livestock: The Pacific Institute, in a 2013 report, estimated that 60 percent of agricultural production in the basin feeds beef cattle, dairy cattle, and horses (Cohen 2013). Agriculture has always been, and will remain, a key piece of the Colorado River puzzle.

But almost as quickly as the Bureau of Reclamation began diverting water for agriculture, other needs arose, from producing electricity to slaking the thirst of booming Los Angeles. By the early 1920s, the seven states of the arid West realized they had to find a way to share a river that would become—as the river’s preeminent historian, the late Norris Hundley, would later write—“the most disputed body of water in the country and probably in the world” (Hundley 1996). Years later, Hundley famously referred to the area as a “basin of contention” (Hundley 2009).

Today, dozens of laws, treaties, and other agreements and rulings collectively called the Law of the River govern the use of Colorado River Basin water. They include federal environmental laws, a treaty over salinity, amendments to treaties, a U.S. Supreme Court case, and interstate compacts. None is more fundamental than the Colorado River Compact of 1922, which still guides the annual share of water each state gets. Representatives of the seven basin states hammered out its provisions in grueling meetings held near Santa Fe. They were driven by both ambition and fear.

Ambitious California needed federal muscle to tame the Colorado River if it was to realize its agricultural potential. Los Angeles had aspirations, too. In the century’s first two decades, it had grown more than 500 percent and wanted the electricity that a large dam on the river could deliver. A few years later, it also decided it wanted the water itself. To pay for this giant dam, California needed federal help. Congress would approve that aid only if California had secured support from the other southwestern states.

Fear drove the other basin states. If the first-in-time, first-in-right legal system of prior appropriation used by Western states was to be applied to the Colorado River, California and perhaps Arizona would reap the benefits. The headwaters states, including Colorado, were developing too slowly to benefit from their own long and snowy winters. Delph Carpenter, a Colorado farm boy turned water lawyer, forged the consensus. Both basins, upper and lower, got 7.5 million acre-feet, for a total of 15 million acre-feet. Mexico needed water, too, which the compact assumed would come from surplus waters. A later treaty between the two nations specified 1.5 million acre-feet for Mexico.

The 1922 Colorado River Compact also nodded, but no more, at what later writers called a sword of Damocles hanging over these allocations: water for the basin’s Indian reservations. The U.S. Supreme Court, in a 1908 case called Winters v. United States, had declared that when Congress reserved land for a reservation, it implicitly reserved water sufficient to fulfill the purpose of that reservation, including agriculture. That ruling did not determine the amounts that were needed. Tribal water rights within the basin now constitute 2.4 million acre-feet, in many cases senior in priority to all other users within the allocations of the individual states. That’s a fifth of the river’s total flows. Importantly, specific water allocations for some of the largest tribes still have not been resolved.

The framers of the 1922 compact made a big, fatally flawed assumption: That enough water existed to meet everyone’s needs. Average annual flows from 1906 to 1921 had averaged 18 million acre-feet. But even by 1925, just three years after the Compact came into being and three years short of its Congressional approval, a U.S. Geological Survey scientist named Eugene Clyde La Rue had delivered a report indicating the river probably would deliver too little water to meet these hopes and expectations. Other studies about the same time delivered the same conclusions.

They were right. Over a longer period, from 1906 to 2018, the river has averaged 14.8 million acre-feet per year. Averages have dropped during the twenty-first century, in the midst of a 19-year drought, to 12.3 million acre-feet. In the last water year, ending in September 2018, the river carried only 4.6 million acre-feet. That’s just 200,000 more acre-feet than California’s annual entitlement.

The Shift from Farms to Cities

Agriculture was the main driver of development along the Colorado River. According to a recent report from the U.S. Geological Survey, 85 percent of water withdrawals went toward irrigation between 1985 and 2010 (Maupin 2018). The fields around Yuma, Arizona, and the Imperial and Palo Verde valleys of California consume more than 4 million acre-feet of Colorado River water annually, nearly a third of the river’s annual flows. But with population growth, water use has shifted to urban needs.

In Colorado, for example, 95 percent of water imported from the Colorado River headwaters through the Colorado-Big Thompson (CBT) project was once used for agriculture; now, that number is closer to 50 percent. As another example of the complexity of systems in the Colorado River Basin, CBT water is divided into units which can be bought and sold. The amount of water in a unit varies year to year depending on the total amount of water available; when CBT is at full capacity, a unit is one acre-foot. Agricultural users owned 85 percent of the units when trading began in the late 1950s, but currently own less than one-third of available units. Municipalities own the balance, but often lease the water to farms until it’s needed. The current price for a CBT unit is close to $30,000.

Such water-sharing agreements are becoming more common in a system stretched too thin. Rotational fallowing, also known as lease-fallowing or alternative-transfer mechanisms, has played a role in shifting water from farms to cities. Farmers in the Palo Verde Valley struck a deal with the Metropolitan Water District of Southern California, which serves 19 million customers, to fallow between 7 and 35 percent of their land on a rotating basis. Metropolitan’s customers, in turn, get the water, which can be stored in Lake Mead. Similar deals, still underlined with tension but increasingly accepted, exist between Southern California municipalities and farmers in the Imperial Valley and between cities and farmers along Colorado’s Front Range urban corridor.

For their part, cities tend to tout conservation and development efforts they’ve made with water in mind. Many are encouraging density, reducing the water needed for landscaping; some have implemented turf-removal programs; and toilets, showers and other fixtures have become more efficient. Metropolitan Water District of Southern California chalked up a 36 percent per capita reduction in water use from 1985 to 2015, a time of several droughts, according to Planning magazine (Best 2018).

In Nevada, the population served by the Southern Nevada Water Authority has increased 41 percent since 2002, but the per capita consumption of Colorado River water fell 36 percent. The agency’s Colby Pellegrino, speaking at a September 2018 conference called “Risky Business on the Colorado River,” said conservation is the first, second, and third strategy for achieving reduced water consumption. “If you live in the Las Vegas Valley, where there is less than 4 inches of rainfall a year, and you have a median covered in turf, and the only person walking on that turf is the person pushing a lawn mower—that is a luxury our community cannot afford, if we want to continue to have the economy we have today,” she said.

Economy, culture, and values have been at the core of the basinwide debate about how to respond to the drought. No one sector or region can absorb the full burden of necessary reductions, and it’s clear that everyone must begin to think differently. Speaking at the “Risky Business” conference, Andy Mueller, general manager of the Colorado River Water Conservation District, put it this way: Instead of the intentional use of water, Colorado is now talking about the intentional non-use of water. As is everyone who lives and works in the Colorado River Basin.

A River Shared

In late 1928, Congress approved the Boulder Canyon Project Act. This legislation accomplished three significant things: It authorized construction of a dam in Boulder Canyon, near Las Vegas, which was later named Hoover Dam. The law also authorized construction of the All American Canal, crucial for developing the productive farmland of California’s Imperial Valley, an area that’s now the single largest user of Colorado River water. And the Boulder Canyon Project Act divided waters among the Lower Basin states: 4.4 million acre-feet each year to California, 2.8 million acre-feet to Arizona, and 300,000 acre-feet for Nevada. Las Vegas then had a population of fewer than 3,000 people.

As the twentieth century rolled on, headwaters states also got dams, tunnels, and other hydraulic infrastructure. In 1937, Congress agreed to bankroll the Colorado-Big Thompson Project, what historian David Lavender called a “massive violation of geography” intended to divert Colorado River waters to farms in northeastern Colorado, outside of the hydrological basin. In 1956, Congress approved the Colorado River Storage Project Act, authorizing a handful of dams, including Glen Canyon.

Only Arizona remained left out. It had vigorously opposed the 1922 compact, then remained defiant. Its Congressional representatives opposed Hoover Dam and, in 1934, then-Governor Benjamin Moeur even dispatched the state’s National Guard in a showy opposition to construction of another dam being built downstream to deliver water to Los Angeles. “Put simply, Arizonans feared there would be little water remaining for them after the Upper Basin, California, and Mexico got what they wanted,” Hundley explains (Hundley 1996). Finally, in 1944—the same year the U.S. and Mexico reached an agreement about the amount of water due to the latter—Arizona legislators succumbed to political realities. Cooperation, not confrontation, would be needed for the state to get federal help to develop its share of the river. At last, the compact had the signatures of all seven states.

Arizona finally got its big slice of Colorado River pie in the 1960s. A U.S. Supreme Court decision in 1963—one in a series of Arizona vs. California cases over many decades—confirmed Arizona had the right to 2.8 million acre-feet, as Congress had specified in 1928, along with all the water in its own tributaries. This is what Arizona had wanted all along. In 1968, Congress approved funding for the massive Central Arizona Project, ultimately resulting in the construction of 307 miles of concrete canal to deliver water from Lake Havasu to Phoenix and Tucson and farmers between. California supported the authorization, with a hitch: In times of shortage, it would still have rights to its 4.4 million acre-feet first. This led Arizona to later create a water banking authority to store Colorado River in underground aquifers, providing at least partial security against future shortages.

Upper Basin states had reached accord about how to apportion their 7.5 million acre-feet without notable friction: Colorado 51.75 percent, Utah 23 percent, Wyoming 14 percent, and New Mexico 11.25 percent. They used percentages, as Hundley explained, because of “uncertainty over how much water would remain after the upper basin had fulfilled its obligation to the lower-basin states” and Mexico. Fluctuations in the river’s flow, they reasoned, might mean that some years they had an amount smaller than 7.5 million acre-feet to divide between themselves. It was, in retrospect, an eminently wise decision.

Conservation Concerns

The same year the basin states framed the original Colorado River Compact, the great naturalist Aldo Leopold canoed through the Colorado River Delta in Mexico. In an essay later published in A Sand County Almanac, he described the delta as “a milk and honey wilderness.” The river itself was “nowhere and everywhere,” he wrote, and was camouflaged by a “hundred green lagoons” in its leisurely journey to the ocean. Six decades later, visiting the delta after a half-century of feverish engineering, construction, and management had emerged to put the river’s waters to good use, the journalist Philip Fradkin had a different take. He called his book A River No More.

As the 20th century closed, the environmental impacts of essentially regarding a river as plumbing drew new attention, especially in the now dewatered delta. The lagoons that had so enchanted Leopold were gone, because the stopped-up river no longer reached its southern outlet. Drainage from vast agricultural enterprises had made the river so saline that, among other things, Mexico protested that the water it was receiving was unfit to use. The many dams and diversions that came after Leopold’s visit had also put 102 river-dependent rare birds, fish, and mammals on the brink of extinction, reported the Arizona Daily Star. The newspaper lauded the work of stakeholders in a new transborder conservation effort: “The fundamental principle of ecology calls for land managers to look to the good of the whole system, not just its parts.”

Environmental groups might have used the Endangered Species Act to force the argument about solutions, but the delta was not within the United States. So they looked to find collaborative solutions. In the closing days of the tenure of Bruce Babbitt, secretary of the Interior in the Clinton administration and namesake of the Babbitt Center, the two countries adopted Minute 306. It created the framework for a dialogue that produced, under Babbitt’s successors in the Bush administration, an agreement called Minute 319 and a one-time pulse flow of more than 100,000 acre-feet in the river in 2014.

Children gleefully splashed in the rare waters of the river in Mexico during that pulse flow, but adults on both sides of the border were equally happy. Among those grinning was Jennifer Pitt, then of the Environmental Defense Fund. Litigation had been a possible route, she said, but an inclusive and transparent process with stakeholders was more productive.

“The institutional legal and physical framework we have on the Colorado River is the basis for great competition and the potential for litigation between parties,” says Pitt, who is now with Audubon. “But it is exactly that same framework that has given those parties the opportunity to collaborate as an alternative to having solutions handed to them by a court.”

Collaboration Is Critical

Reservoirs were full as the next century arrived, thanks to robust snowfall in the Rockies during the 1990s. Still, there was tension. California for decades had exceeded its apportionment of 4.4 million acre-feet, consuming a high of 5.4 million acre-feet in 1974. Upper Basin states never have fully developed their 7.5 million acre-feet, averaging 3.7 to 4 million since the 1980s, plus 500,000 acre-feet from reservoir evaporation.

Then came drought, deep and extended. The river carried just 69 percent in 2000. The winter of 2001 to 2002 was even more stingy, the river delivering just 5.9 million acre-feet, or 39 percent of average, at Lake Powell. From 2000 to 2004 was the lowest 5-year cumulative flow in the observed record. Since then, more years have been dry than wet. The reservoir levels are at near-record lows.

The 1922 compact had not contemplated this kind of long-term drought. A structural deficit came into sharp relief. Tom McCann, assistant general manager of the Central Arizona Project, coined the phrase. Very simply, the Lower Basin states were using more water than was delivered from Lake Powell each year. This was so even when the Bureau of Reclamation authorized the release of extra “equalization” flows from Powell.

“Equalization releases are like hitting the jackpot on the slot machine,” McCann says. “Back then, we were hitting the jackpot every three or four or five years, and we thought we had nothing to worry about.” Even with the jackpots, Lake Mead continued to decline, the reservoir’s widening bathtub ring charting the losses.

Climate change overlays the structural deficit. Scientists argue that warming temperatures swing a big bat in the Colorado River Basin. They term the early-twenty-first-century declines a “hot drought” as distinguished from a “dry drought.”

The prospect of this new, human-induced “hot” drought on top of a conventional drought worries many. Tree-ring studies show that the region has suffered longer, deeper droughts in the past, before measurements began. “A number of folks claim that the current 19-year period of 2000 to 2018 is the driest 19-year period on the Colorado River,” says Eric Kuhn, former general manager of the Colorado River Water Conservation District. “Nonsense. It’s not even close. If these past droughts were to happen with today’s temperatures, things could be much worse.”

The first two decades of the new millennium have seen a series of efforts to confront this new reality. In 2007, the Department of the Interior issued interim shortage guidelines, the first formal response to the drought. The Bureau of Reclamation released a Basin Supply and Demand Study in 2012, an exhaustive effort to provide a platform for future decisions. The many reports stacked tall enough to fill a box that could ship a football. They discussed population growth, rising temperatures, and the impact of increasing rain on snowpack. Demand, the study concluded, would exceed supply by 3.2 million acre-feet by 2060 (USBR 2012).

“You can argue about the numbers, you can argue about the forecast, but it was something that got everybody’s attention,” says Colorado’s Anne Castle, who was then assistant secretary of Interior for water and science. “It served as a catalyst to focus the discussion about Colorado River management more directly in dealing with future scarcity.”

Castle sees the basin now struggling to find collaborative solutions. “In a complex water system, there are so many moving parts, it’s not about one answer,” she says. “You have to manage a complex system, and you can only do that through negotiated agreements.”

Those negotiations are happening now, in the form of drought contingency planning. Even as scarcity has become more prominent, collaboration has also grown. But the measuring stick for success may well be the white mineralized walls of Lake Mead, a big reservoir in a big basin facing big challenges. Now the seven states, the tribes, and the governments of the U.S. and Mexico, with input from environmental and other nongovernmental organizations, must figure out how to keep those water levels from sagging even more. They must concoct a plan that ensures a sustainable future, while heeding the twists and turns of the past.

Allen Best writes about water, energy, and other topics from a base in metropolitan Denver, where 78 percent of his water comes from the Colorado River Basin.

Photograph: Lake Powell at Glen Canyon Dam. Credit: Pete McBride.

References

Arizona Daily Star. 1998. “Don’t Ignore Colorado Delta.” May 6, 1998.

Best, Allen. 2018. “Water Pressure: Smart Management Is Key to Making Sure Inland Cities Aren’t Left High and Dry in the Face of a Warming Climate.” Planning August/September: 40–45. https://www.planning.org/login/?next=/planning/2018/aug/waterpressure/.

Cohen, Michael, Juliet Christian-Smith, and John Berggren. 2013. Water to Supply the Land: Irrigated Agriculture in the Colorado River Basin. Oakland, CA: Pacific Institute. (May). http://pacinst.org/publication/water-to-supply-the-land-irrigated-agriculture-in-the-colorado-river-basin/.

CRRG (Colorado River Research Group). 2018. “It’s Hard to Fill a Bathtub When the Drain is Wide Open: The Case of Lake Powell.” Boulder, CO: Colorado River Research Group. (August). https://www.coloradoriverresearchgroup.org/uploads/4/2/3/6/42362959/crrg_the_case_of_lake_powell.pdf.

Fradkin, Philip. 1996. A River No More: The Colorado River and the West. Oakland, CA: University of California Press.

Hundley, Norris Jr. 1996. “The West Against Itself: The Colorado River—An Institutional History.” In New Courses for the Colorado River: Major Issues for the Next Century, ed. Gary D. Weatherford and F. Lee Brown. Albuquerque, NM: University of New Mexico Press. http://web.sahra.arizona.edu/education2/hwr213/docs/Unit1Wk4/Hundley_CRWUA.pdf.

———. 2009. Water in the West: The Colorado River Compact and the Politics of Water in the American West. Oakland, CA: University of California Press.

Leopold, Aldo. 1949. A Sand County Almanac: And Sketches Here and There. New York, NY: Oxford University Press.

Maupin, Molly A., Tamara Ivahnenko, and Breton Bruce. 2018. “Estimates of Water Use and Trends in the Colorado River Basin, Southwestern United States, 1985–2010.” Reston, Virginia: U.S. Geological Survey. https://pubs.er.usgs.gov/publication/sir20185049.

USBR (U.S Bureau of Reclamation). 2012. “Colorado River Basin Supply and Demand Study.” Washington, D.C.: U.S. Department of Interior. https://www.usbr.gov/lc/region/programs/crbstudy/finalreport/Study%20Report/CRBS_Study_Report_FINAL.pdf.

Worster, Donald. 1985. Rivers of Empire: Water, Aridity, and the Growth of the American West. New York, NY: Pantheon Books.

YCAWC (Yuma County Agriculture Water Coalition). 2015. “A Case Study in Efficiency: Agriculture and Water Use in the Yuma, Arizona Area.” Yuma, AZ: Yuma County Agriculture Water Coalition. (February). https://www.agwateryuma.com/wp-content/uploads/2018/02/ACaseStudyInEfficiency.pdf.