Steven Solomon
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By breaking the political logjam over the Colorado, the landmark agreement with Imperial Valley paved the way in late 2007 for a second breakthrough accord—an emergency plan among the Colorado River compact states about how to allocate scarce water among themselves should the river flow fall below the 7.5 million acre-feet promised to the lower basin. Given the downward revision in the Colorado’s long-term average flow to only 14 million acre-feet per year, and with Lake Mead only half full because of a severe drought, such an emergency was likely to occur; moreover, with climate change models forecasting a 20 percent decline in rainfall compared to most of the twentieth century, and shrinking annual mountain snowpacks exacerbating summer shortfalls, the emergency seemed likely to strike sooner rather than later. The shared sense of impending crisis spurred unusual, proactive efforts to improve the productive use of existing water supplies before the crisis threshold was crossed.
The 2007 emergency accord included innovative market and ecosystem-management arrangements that stimulated interstate water trades and consumption reductions by allowing users to bank their savings in Lake Mead or aquifers for later use. Fast-growing, desert-bound Las Vegas, for instance, offered to pay for new water storage facilities or desalinization plants in California in exchange for an extra draw on California’s Colorado River allotment. Las Vegas was already one of the most conservation efficient cities. Every drop of its sewage wastewater is treated and released into Lake Mead, where it is further purified by dilution and pumped back to the city’s taps. Even with its growing population, water use has fallen from its peak in 2002 thanks to various conservation methods, including promotion of low-flow toilets and appliances, paying residents to replace water-thirsty lawns with natural desert flora, and higher consumer prices. In the eastern Rockies, the city of Aurora, Colorado, was creating a recycling loop even more elaborate than Las Vegas’s. It was buying agricultural land downstream along the South Platte River so it could draw water that had been naturally filtered by the sandy riverbanks through a series of adjacent wells. The water was then to be pumped to the city in a 34-mile-long pipeline, purified, used, treated, discharged back into the river, and then recaptured in the riverbank wells to start a new circuit. Each round-trip took forty-five to sixty days and recycled half of every drop.
Spurred by continuing drought, California introduced a state water bank that allowed northern California farmers to sell their seasonal water rights on fallowed land to farmers using more efficient farming techniques and growing more valuable crops. In 2009, the state-set price for watering parts of California’s fertile, but naturally arid and badly overpumped Central Valley, was $500 an acre-foot—nearly three times the price of 2008, but still far below what the free-market price would likely have fetched. Coastal Southern California has also been turning to wastewater recycling to supplement drinking supplies because all available local and aqueduct-delivered natural water supplies had been exhausted. The Colorado River had maxed out. Mountain snowmelt and reservoir levels were diminishing with drought and global warming. Even long-distance freshwater piped from northern California was being curtailed, as court rulings and federal restoration for the Central Valley elevated the priority of conserving water to improve the health of the fish and wildlife of the depleted ecosystem of the San Joaquin–Sacramento River delta estuary and San Francisco Bay. With population growth forecasts still rising, Los Angeles and San Diego, as a last resort, were turning to large-scale recycling and purification of sewer wastewater—long used for irrigation and lawn watering—to augment urban drinking supplies.
The disparaging name critics label such projects—“toilet to tap”—is a misnomer. Not only is the wastewater intensively cleansed to a level that can be purer than naturally derived tap water; it does not go straight to the tap, either. Instead it is injected into the ground to be further filtered by natural aquifers before being drawn into public drinking supplies. There is little novelty in the concept. For decades, cities across the United States routinely discharged their treated sewage, or effluent, into local rivers such as the Colorado, the Mississippi, and the Potomac, where in diluted form it was taken into the drinking supply of cities downstream. The same principle had been followed by London in building its sanitary system in response to the mid-nineteenth-century Great Stink. The Southern California recycling projects differ in using slow-moving groundwater instead of surface river flows to do the additional natural filtering. The pioneering prototype was the facility that opened in January 2008 in Orange County, California, which has a capacity of 70 million gallons per day. Its labyrinth of tubes and tanks take in dark brown treated sewage water, then remove solids with microfilters and smaller residue through high-pressure reverse osmosis before a final cleansing with peroxide and ultraviolet light. The final product, as pure as distilled water, is injected into the aquifer for natural filtering before entering the public drinking supply. Water managers in water-stressed southern Florida, Texas, and San Jose, California, have been contemplating similar projects to help meet their future needs. Only one major city in the world—Windhoek, in Africa’s arid Namibia—actually recycles water on a large scale from treatment plant directly to the drinking tap. Yet aside from the revolting idea of the source of such water, there is no technological, or cost-efficiency obstacle to believe that such truly closed, recycled infrastructure loops will not become more commonplace as the age of water scarcity advances.
Water shortage is also propelling Southern California’s leadership in a modest global movement toward state-of-the-art desalinization technologies. Desal costs in California had fallen from $1.60 to 63 cents per cubic meter between 1990 and 2002, putting it on par with large, efficient reverse osmosis plants built in water-starved Israel, Cyprus, and Singapore. By 2006, there were enough proposals for new seawater desal plants to increase California’s capacity a hundredfold, and supply up to 7 percent of the entire state’s urban water use. The first major test of desal’s mass production capabilities in California was joined in 2009 with a decision to build a giant, reverse osmosis plant near San Diego that was projected to produce 50 million gallons of drinking water daily from the ocean by 2011—10 percent of northern San Diego’s requirements. While total desalinization capacity is still very small, California’s sheer size and its special, water trendsetting status makes it a potential catalytic tipping point—especially if coupled with breakthroughs whereby solar or wind power can substitute for nonreplenishing and polluting fossil fuel energy—for the long hoped for takeoff of water desalinization.
A half century earlier, President John Kennedy had expressed mankind’s age-old dream of desalination. “If we could ever competitively—at a cheap rate—get fresh water from salt water,” he mused, “that would be in the long-range interest of humanity, and would really dwarf any other scientific accomplishment.” Ever since man first took to the seven seas, sailors had dreamed of desalting seawater. Long-distance European mariners in the Age of Discovery pioneered the installation of primitive desalting equipment for emergencies. Crude, large-scale water desalting was enabled by advancements in the distillation process made in the mid-nineteenth century by the sugar refining industry. Modern desalinization, however, was brought to fruition by the U.S. Navy, which developed it during World War II to provide water to American soldiers fighting on desolate, South Pacific islands. By the 1950s, a thermal-desalinization process based on steam-pressure-induced evaporation was developed; although very expensive, it was adopted on a fairly large scale in Saudi Arabia and other oil rich, waterless coastal nations of the Middle East. Also in the 1950s, the American government supported university research for a better desalinization technique—the reverse osmosis process was invented during Kennedy’s presidency and was put into action on a small scale using brackish water in 1965. With the development of a much-improved membrane in the late 1970s, reverse osmosis desalinization plants for seawater became possible. Since they required enormous amounts of energy and the water they produced was s
o costly compared to water obtained by other means, it was unsurprising that the first big city desal plant was opened in Jedda, Saudi Arabia, in 1980, where energy was cheap and water pricelessly scarce.
Major improvements in energy recovery techniques and membrane technologies occurred with such speed from the 1990s that by 2003 desal costs had fallen by two-thirds, and desal was becoming a viable component of the diverse portfolio of water supply solutions being adopted in water-famished, coastal regions where supply was abundant and expensive long-distance water pumping unnecessary. Perth, Australia, for instance, got nearly one-fifth of its water from desalinization. Israel’s desal share was poised to rise rapidly and desal offered hope of quenching some of the mounting thirst in the Muslim Middle East and North Africa. Reverse osmosis membrane technologies at the heart of desalinization were also being applied in recycling wastewater in Orange County’s pioneering plant and in Singapore, where it helped replenish local reservoirs. With growth stirring in desal, major corporations were gearing up to win market share in order to earn large profits as the market developed. Projections of market growth in the decade to 2015 ranged widely, from a trebling to a septupling of the $4 billion spent in 2005.
On its most optimistic projections, however, desalinization cannot be the panacea technology to solve the world’s water crisis in the short term. Installed desal capacity is simply too tiny—a mere 3/1,000ths of 1 percent of the world’s total freshwater use. Even if costs plunged, there are unsolved environmental problems about how to dispose of the briny waste; inland regions cannot be reached without expensive pumping and building long aqueducts. In the most likely, best case scenario, desal will become one of a portfolio of freshwater supply techniques that help countries muddle through their scarcity crises.
In the rainy, temperate eastern half of America, New York City, the nation’s urban trendsetter in long-distance water storage and delivery systems, is also in the vanguard of the new soft-path movement. One of its most closely watched experiments is to exploit the natural, cleansing services of forested watersheds to improve the wholesomeness of its drinking water—and simultaneously save billions of dollars for the region’s 9 million inhabitants. Ever since its gravity-fed Croton water system opened in 1842, New York had routinely extended its aqueducts and reservoirs farther and farther upstate into the Catskill Mountains and the upper reaches of the Delaware River to obtain more clean freshwater. By the 1990s New York City’s water network featured three distinct water systems with one and a quarter year’s storage capacity that delivered 1.2 billion gallons per day from 18 collecting reservoirs and three lakes in upstate New York. But a serious problem of deteriorating water quality had been building as the pristine rural, forested countryside surrounding the reservoirs degraded with modern development and farming. As a result, half the city’s reservoirs were chronically choked with poisonous phosphate and nitrogen runoff from dairy farm pastures and over 100 sewage treatment plants that depleted oxygen levels and produced foul, algae blooms, as in China’s Lake Tai, that killed cleansing biological life. When U.S. fresh drinking water standards were toughened in the late 1980s, New York City faced an ultimatum: build a state-of-the-art filtration plant—at a staggering cost of $6 to $8 billion, exclusive of the huge operating expenses of the energy-intensive filtration facility—or devise an alternative method to protect the quality of the city’s water.
New York’s innovative response was a $1 billion plan to improve the upstate forests and soils surrounding the reservoirs so that they conserved more water and filtered out more of the pollutants in a natural way—in effect, New York was enhancing the natural watershed ecosystem and putting a market value on its antipollution services in place of far more expensive, traditional, artificial cleansing infrastructures. Also remarkable was that New York’s ecoservices project was forged by a new, politically inclusive consensus among city and state officials, environmentalists, and rural community representatives. Their multiyear negotiation was formalized in a 1,500-page, three-volume agreement signed in January 1997.
At the heart of the plan, New York City would spend $260 million to purchase some 355,000 acres—nearly twice the geographic area of the city itself—of water sensitive land from voluntary sellers to buffer the reservoirs. Some of the new city-owned land would be open to the public for recreational fishing, hunting and boating, and leased to private interests for environmentally controlled commercial activities such as growing hay, logging and production of maple syrup. Up to $35 million more would be spent to clean up and modernize several hundred dairy farms—including reducing their water consumption in milk production by up to 80 percent—to help them compete against the encroachment of concrete road polluting and waste-producing subdivisions. To mollify local communities still resentful of the city’s imperious, historical use of compulsory sales to acquire watershed land for its reservoirs, the city agreed to spend another $70 million for sundry infrastructure repairs and environmentally friendly economic development. A new environmental division was created within the city’s century-old watershed police force; armed with chemistry kits and looking for leaky septic tanks and rivulets of frothy, toxic discharges, they patrolled the countryside and subdivisions to protect the reservoirs. In effect, New York City has created a market price for the ecosystem services provided by its watershed. A decade later, it took another step toward marrying ecosystem sustainability and market economics by negotiating a complicated land swap with a big resort developer whereby a public forest acquired watershed-protective mountainside real estate in exchange for a smaller resort project on a less environmentally sensitive side of the mountain. The developer also agreed not to build on runoff-prone steep slopes or use chemical fertilizers on its golf courses.
The early results of New York City’s watershed experiment are auspicious. Environmentalist watchdogs gave New York City good grades for drinking-water quality in 2008—a year after the city had won a further conditional ten-year filtration plant exemption from the U.S. Environmental Protection Agency. In economic terms the program had saved the city up to $7 billion in unnecessary construction, expanded recreational revenues, and augmented the long-term sustainability of New York’s water supply. With continued success, it offered a potential template for the next generation of urban water development. Indeed, other American cities, and some abroad including Cape Town, South Africa; Colombo, Sri Lanka; and Quito, Ecuador, also adopted variants of New York–style ecosystem service valuations to help solve their local challenges.
With echoes of both New York and Southern California, Florida’s governor Charlie Crist launched in 2008 a novel initiative to revive a moribund restoration plan for the state’s famous wetlands, the dying Everglades. For nearly a decade, a joint federal-state plan had been held hostage by the political grip of the state’s water-guzzling, phosphate-polluting, and price-subsidized big sugarcane farmers. Deprived of clean water, half the Everglades had already dried up. By spending $1.34 billion in state funds to buy 181,000 acres of land from the giant U.S. Sugar Corporation, Crist opened the way for a land swap with other agribusinesses that would open channels to renew the historic flow of fresh, clean water to the Everglades from Lake Okeechobee.
In addition to enhancing its upstate watersheds to improve the quality of the water entering its reservoirs and aqueducts, New York City also embarked on a showcase water conservation program in the early 1990s aimed at trimming the system’s total demand, thus reducing the absolute volume that had to be supplied and subjected to expensive purification and wastewater treatment. First, water and sewerage rates were raised sharply toward market levels to discourage wasteful use. A highly publicized, $250 million toilet rebate program for poorer families was also launched to jump-start a citywide trade-in of old 5- and 6-gallon toilets for newer toilets that consumed only 1.5 gallons per flush. Toilets are by far the biggest single water consumer in the household—accounting for about a third of consumption—and in 1992 the government mandated a gradual na
tional conversion to low-flow models. By 1997 the toilet replacements, higher prices, and other measures, including comprehensive metering and leak detection, helped New York’s daily water consumption to plunge dramatically to 164 gallons per person from nearly 204 gallons in 1988—a 20 percent savings, or 273 million gallons per day. As a result, New York officials projected that the city would not need any additional water supply for another half century, while incalculable millions of dollars were saved on sewage treatment and pumping. The replication of New York’s conservation methods by cities across the United States has been one of the driving forces behind the unprecedented increase in America’s water productivity since the 1980s.
New York City faced one other gargantuan challenge, however, for which it had no low-cost, water-productivity-enhancing alternative to old-fashioned, large government expenditure—the decrepit, leaky and potentially failing state of vital components of its aging water infrastructure. Significant leaks had sprung below ground in the original aqueducts that conveyed water from its upstate reservoirs, beneath the Hudson, to a final storage reservoir on the city’s outskirts in Yonkers. More threatening still, New York’s two, leaky urban distribution tunnels, completed in 1917 and 1936, respectively, which conducted water from the Yonkers reservoir throughout the city, hadn’t been shut down for inspection for over half a century for fear they might fail catastrophically—forcing the evacuation of large portions of New York. From 1970, New York tunnel crews had been laboriously drilling through the solid bedrock 600 feet underground—some 15 times below the depth of the subway—to construct a modern, third tunnel that would enable the original two to be shut down and rehabilitated. The $6 billion Tunnel Number 3 was the largest construction work in New York City’s history and one of the most monumental, although invisible and virtually unknown, civil engineering feats of the era—a subterranean descendant of the Brooklyn Bridge and Panama Canal. Until the day it was finished and ready for service, around 2012, New York would continue to live in a slow-motion race against time and potential disaster.