Where the water goes, p.25
Where the Water Goes, page 25
Desalination is more economical if the water it processes is less salty than seawater—say, brackish water from a river estuary, or recycled water that’s too salty to be reused even for irrigation, or formerly pure groundwater that has become excessively saline as rising sea levels have pushed saltwater intrusion farther inland. And there are parts of the world where desalination is the only source of freshwater—among them Dubai, which would be uninhabitable without it. The places that depend on it now tend to be places that are not just undersupplied with water but also oversupplied with fossil fuels, which the process consumes a lot of. (The electricity that runs the Tampa facility is generated by burning coal at the power plant next door.)
The number of desalination facilities all over the world is expected to rise dramatically during the next few decades, as freshwater supplies in more and more regions come under stress from population growth, over-pumping, rising sea levels, declining precipitation, and other factors. One ominous environmental consequence of that trend, with significant climate implications, is that the energy required to operate facilities that haven’t been built yet is energy that the world isn’t currently using. That is to say, increasing global reliance on desalination will enlarge the world’s energy load, by adding a big new category to our already quite long list of energy uses—like installing central air-conditioning in a building whose occupants have always cooled themselves only by opening their windows. And doing that will inevitably increase the world’s reliance on fossil fuels, either directly (if the new desal plants run on fossil fuels) or indirectly (if they run on non-carbon energy that otherwise could have been used for something else). Another worrisome environmental consequence, especially as the equipment becomes more common and therefore cheaper, is that desalination can make it possible for people to undertake environmentally disastrous development in places that couldn’t have supported it otherwise—as in Dubai. Technological innovation isn’t always a solution to environmental problems.
CLOUD-SEEDING
At the Colorado River Water Users Association meeting in 2014 in Las Vegas, Don Ostler, the executive director of the Upper Colorado River Commission, gave a presentation about the Wyoming Weather Modification Pilot Program, a cloud-seeding experiment he’d participated in. The purpose of the experiment, which ran for several years and was paid for mostly by Wyoming, was to assess the feasibility of increasing snowpack in three targeted mountain areas by shooting silver iodide from twenty-foot-tall towers on the ground into moisture-laden clouds above them. One of the three mountain areas was in the drainage basin of the Green River, a tributary of the Colorado. The hope was that the silver iodide would stimulate the formation of ice crystals, which would then fall as snow, which would eventually melt and run into the river. The conclusion of the people running the experiment was that cloud-seeding had increased precipitation in some of the test areas by between five and fifteen percent. Ostler described the technique as one of the most economical strategies for augmenting the Colorado River—although it didn’t work everywhere and (to my eye, at least) the gains weren’t huge.
One interesting aspect of the experiment is that Wyoming didn’t stand to gain from it directly. “The storage we’re trying to protect is below all our users,” Ostler said. That is, the goal was to provide additional water for Lake Powell and Lake Mead, which are far downstream from Wyoming. The lower-basin states contributed money to the project, but the upper-basin states had an interest, too, because by the terms of the compact they’re not allowed to deprive the lower-basin states of their compact entitlements. The full implications of that provision in a period of extended drought haven’t been tested legally—the wording is ambiguous, even if the compact itself is upheld—but, once again, not even the upper-basin states are eager to subject a major component of the Law of the River to a full review in the courts, at least for the time being.
Cloud-seeding seems like moving money from your right pocket to your left, since rain that falls in one place can’t fall in another. But, since one of the predicted effects of climate change is a catastrophic increase in precipitation in places that already have more than they need, maybe everything would balance out—assuming, of course, that it can actually be made to work, and that spraying silver iodide into the atmosphere doesn’t turn out to be a terrible idea for some other reason.
AGRICULTURE
People who live on farms that are irrigated with Colorado River water often accuse people who live in cities of causing shortages by taking water that doesn’t belong to them, but throughout the western United States the main water consumers are farms, not cities. Agriculture accounts for roughly eighty percent of all Colorado River water consumption throughout the river’s entire drainage basin. (Jim Lochhead, the CEO of Denver Water, told me, “We serve a quarter of the state’s population and well over a quarter of the state’s economic activity, yet we use only two percent of the state’s water.”) That means that even large cities could cut back by double-digit percentages without having much impact on total overuse, and that most serious conservation efforts necessarily focus on agriculture. But reducing water use by farmers isn’t as straightforward as it may sound.
The day after Jennifer Pitt and I flew over the Colorado’s headwaters with David Kunkel, a different LightHawk pilot, Andy Young, flew us to a different part of the state, well away from the mountains and the Colorado’s drainage basin. Our route took us directly over downtown Denver and then south, past Colorado Springs. We were roughly a thousand feet above the ground, Young said, and from that altitude it was easy to see which people kept junk in their yards and which people didn’t. I also noticed many fewer backyard swimming pools than I would have seen on a similar flight over metropolitan Phoenix or Southern California, and Pitt said that that was probably because in Colorado the swimming season is so short that the cost, including the cost of water, is prohibitive. (In much of the state, the presence of a backyard swimming pool reduces, rather than increases, the market value of a house.)
We also passed over some very dry-looking agricultural land. “This is high desert,” Pitt said. “It’s probably not that different from what Denver used to look like, a long time ago.” The terrain beyond the residential areas was mostly brown and treeless, and it was dotted with scrubby-looking brush. The cultivated fields were easy to spot. Some were flood-irrigated with water diverted from small streams or collection ponds, and the topography of the fields was made obvious by color: dark green in low-lying sections, where irrigation water had pooled, and lighter green and brown and gray in more elevated sections, which little or no water had reached. (One of the first steps in making agricultural irrigation more efficient is to level the ground—something farmers in the Imperial Valley have spent decades doing.) Other fields, which were easily identifiable because they were perfectly circular, were irrigated with center-pivot systems, each of which relied on groundwater pumped from a well at its center. We also saw livestock-watering troughs, from which spidery lines radiated in all directions: the paths that thirsty grazing animals had worn into the ground as they converged to drink.
We saw lots more green when we reached the Arkansas River, which arises in the Colorado Rockies near Leadville and crosses southeastern Colorado, west central Kansas, northeastern Oklahoma, and central Arkansas before emptying into the Mississippi. Irrigated fields formed a broad, irregularly shaped green stripe along the river’s course, and within that stripe the river itself meandered from side to side. We could also see an extensive system of irrigation canals and ditches. We flew past what’s left of the Pueblo Chemical Depot, which was once one of the country’s largest storage facilities for mustard gas and other chemical weapons. We flew over the town of Fowler, which lies thirty or forty miles downstream from Pueblo and has a population of about twelve hundred. In 2015, the Colorado Water Conservation Board approved a plan by which the owners of six nearby irrigated farms, who had formed an alliance called the Arkansas Valley Super Ditch, agreed to sell water to Fowler and other municipalities by fallowing some of their fields—and we could see those fallowed fields.
Approval of the Super Ditch plan came with a list of restrictions, including a requirement that no field in the program be fallowed for more than three years out of any ten, and that no more than thirty percent of any farm be dried up at one time. The purpose of the restrictions is to keep the farms functioning as farms, even as they sell off some of their irrigation water to municipal users, and to avoid one of the unanticipated consequences of some other buy-and-dry schemes: the collapse, or near collapse, of the surrounding community, as farms that once supported the local economy shut down. The fallowing of even a few farms in a single irrigation district can be lethal to the entire district if the level of irrigation falls below whatever threshold is needed to keep the ditch system functioning, and if agricultural production falls below whatever threshold is needed to maintain employment levels and farm-dependent local businesses. The approval also included a requirement that the irrigators as a group maintain the “return flows” stipulated by their water-court decrees to protect users downstream (and to maintain compliance with the terms of Colorado’s compact with Kansas regarding diversions from the Arkansas). Pitt told me that Colorado is unique among the states in attempting to devise farm-to-city water-transfer programs that aren’t lethal to farming.
How far to go in protecting farmers, and which ones, is among the more complicated western water issues. “Agriculture” isn’t a monolith; some crops are clearly more valuable than others, even if no one agrees which crops those are. (If I were king, I’d ban growing corn for ethanol—not an issue in the Colorado River basin—long before I thought about going after alfalfa.) But even low-value crops can have high-value human dependents, as in the Grand Valley, and decisions about who survives and who doesn’t shouldn’t necessarily be left to water managers in big cities. Or to energy producers. Kent Holsinger told me that his parents’ cattle ranch (described in chapter 2) was once nearly shut down by a series of local droughts, but that his parents had been able to remain in operation largely because at a critical moment an oil and gas company offered to lease their mineral rights for several years. “The company ended up not drilling, because that area wasn’t terribly attractive, but the money literally tided us over,” Holsinger told me. “Now my parents have a little next egg, and they paid off debt, and the ranch is still in the family.” The larger question is whether the preservation of an irrigated cattle ranch is a good thing or bad thing. As always, the answer depends on your point of view.
WATER FOOTPRINT
People who worry about irrigation often argue that it shouldn’t be used to support “low-value” crops. But economics alone is an unreliable tool for determining what should and shouldn’t be grown—and, as Pitt pointed out to me, “high-value” crops include things like the kinds of thirsty decorative plants that people buy to put in their irrigated yards. How about Halloween pumpkins? Christmas trees? Wine grapes? Pears for hard cider? Organic baby carrots? People who fume about agricultural subsidies—and I have sometimes been one of them—don’t necessarily recall that the beneficiaries of those subsidies include pretty much everyone, since we would all pay more for what we eat if economic protections for farmers didn’t exist. One of the unintended consequences of cutting back on irrigation is that it opens up former agricultural land for sprawling residential development and other “high-value” uses, whose environmental impacts can be more problematic than those of irrigated agriculture. A new subdivision in some especially dry part of the West—say, on the outskirts of metropolitan Phoenix—will almost always use less water than any irrigated farm it replaces. But water use isn’t, or shouldn’t be, the only consideration.
Markets aren’t even all that good at managing markets. (Think of Enron and the Great Recession.) Traditional economists tend to undervalue goods that are hard to pin a price on, like air quality, water quality, and the future of civilization—those pesky “externalities.” Arizona used to be one of the world’s leading producers of cotton; today, the state’s cotton acreage is just fifteen percent of what it was at its peak, in the early 1950s, before state officials began to worry about groundwater. That decline is generally viewed as a good thing, both for Arizona water users and for the environment—but is it really better for humanity if almost all cotton is grown instead in places like China, India, Pakistan, and Brazil (globally, the number one, two, four, and five producers), where freshwater supplies are more dangerously threatened than they are in the United States (number three)? Or maybe humans shouldn’t be growing cotton at all and should instead wear only Under Armour T-shirts, Nike yoga pants, and other clothing made from synthetic fibers. Yet synthetic fibers are made from fossil fuels—and that must be a bad thing, unless it’s better to turn petroleum into clothing than to set it on fire. (These aren’t trick questions; if the answers are obvious, I don’t know what they are.)
The resource footprint of the increasingly finicky preferences of affluent consumers all over the world is a seldom-discussed environmental issue. Larry Cox, the farmer I visited in the Imperial Valley, told me, “The durum wheat we grow for pasta has to have a certain color and a certain protein content or there’s a deduction. The lettuce we sell to a food-service company has to weigh between forty-eight and fifty-two pounds, but the lettuce we grow for a retailer has to be a certain size and can only weigh twenty-eight pounds, and the broccoli we ship to the Pacific Rim might be on a ship for eighteen days, so we have to pick it very young and put it in a controlled-atmosphere bag.” Fast-food chains and other commercial buyers reject potatoes that don’t meet exacting specifications for color and size; ketchup manufacturers are equally picky about tomatoes. Each of those preferences has an environmental impact.
Cox continued, “Even on the citrus we grow—lemons for export have to be different sizes from lemons for domestic. Then we’ve got fancy grade, choice grade, standard grade. We put up thirty-two different packs, between lettuce and broccoli and mixed lettuce and sleeved romaine—and it’s okay, but you kind of feel like a poodle jumping through hoops.” The gourmet infatuation with tiny vegetables has water and energy implications. So does the preference for organic produce, which, because the yields are lower, requires both more water and more land, thereby encouraging “agricultural sprawl,” which the writer James McWilliams defines as “an insidious form of development that threatens the world’s remaining natural resources.” Commercial-scale organic farming also depends heavily, though indirectly, on irrigated forage crops, because doing without synthetic fertilizer means relying on manure, most of which is necessarily produced by livestock—and that means that the water embedded in forage crops is embedded in organic vegetables as well.
THREATS BEYOND THE BASIN
According to Patricia Mulroy, the biggest challenge to the millions of people who depend on water from the Colorado River lies far outside the river’s drainage basin: in Northern California. “You are never going to find long-term stability in the Colorado system,” she told me, “until you stabilize the Bay Delta. It blows people’s minds when I say that, but it’s true.” She was referring to the Sacramento–San Joaquin River Delta in Northern California. Bradley Udall agrees with her; he described the delta to me as “the biggest potential water disaster in the United States.”
The Sacramento River is the largest river in California. It arises in mountains in the far northern part of the state, flows down the center of the Central Valley and through downtown Sacramento, and empties into the Pacific Ocean by way of three connected bays: Suisun, San Pablo, and San Francisco. The San Joaquin River arises several hundred miles to the south, in mountains in the eastern part of central California, and also empties into the Pacific Ocean by way of the same three bays—but from the other side. The region where the two rivers meet is almost always referred to as a “delta”—it’s known variously as the Sacramento–San Joaquin River Delta, the Bay Delta, and the California Delta—but it’s actually an “inverted delta,” because the topography of the Central Valley and Suisun Bay is such that most of both rivers’ sediment load is deposited inland, forming an alluvial fan that seems to spread out in the wrong direction, away from the ocean. That alluvial fan is filled with closely spaced, irregularly shaped islands, and from the air the whole thing resembles an enormous green jigsaw puzzle.
Settlers began growing crops on the delta’s islands in the late 1800s. As they did, the islands’ soil—which consisted largely of marshy accumulations of decaying plant material—began to subside. To keep river water from inundating their fields, the farmers built dikes around the perimeters of the islands, and as their fields sank below the water table they also installed drainage ditches and pumps. Most of the islands today are deeply saucer-shaped. The cultivated fields, which altogether cover more than a thousand square miles, have subsided as much as twenty-five feet below the surface of the river channels that surround them, and the dikes and pumping systems have grown as the challenge of keeping out the bay has increased.
