Drought Mitigation: Water Conservation Tools for Short-Term and Permanent Water Savings
Amy L. Vickers
13.1 Introduction: A New Era of Water Scarcity or an Old Error
of Water Waste?..........................................................................................307
- 13.2 Water Conservation: The Great Untapped Water Supply....................312
- 13.3 Conclusions.................................................................................................320
Introduction: A New Era of Water Scarcity or an Old Error of Water Waste?
The 1882 gravestone of a child that had lain for 129 years beneath the Lake Buchanan reservoir in Bluffton, Texas, resurfaced during a severe drought that began in 2011. For 5 years that memorial (along with remnants of an abandoned bank, a cotton gin, and house foundations in Old Bluffton), which had been abandoned to build nearby Buchanan Dam, baked in the sun during a withering multiyear drought (Hlavaty 2016). Some say the drought brought back the old ghost town, but others shake their heads and point to the water managers and politicians whose actions to reduce water demands were too little and too late. Had officials acted earlier and more aggressively to impose mandatory lawn watering restrictions and other proven water-saving strategies, the reservoir's cool, dark waters would have been preserved over the buried stone structures during the drought.
There have been profound advances in water efficiency, technologies, and conservation practices over the past 20 years that are capable of reducing many urban and agricultural water demands by at least one-third. Despite this, the potential for large-scale water-saving strategies to mitigate if not overcome the impacts of drought and long-term supply shortages has yet to be fully tapped by more than just a few water systems. Those demand-side water supply options are too often ignored—and at our peril. For how long can humanity afford to err in pursuing this most accessible, cost-effective, and environmentally friendly option to help meet our current water needs, let alone those to ensure a water secure future?
"If an alarm bell was needed to focus global attention on water security, it has rung," warns Sandra Postel, international water policy expert, author, and director of the Global Water Policy Project based in Los Lunas, New Mexico (Postel 2016). Exactly how the increasing water demands of the twenty-first century's growing population will be met amidst declining freshwater availability even during nondrought times is, indeed, a formidable challenge. The signs of water stress are daunting: half of the world's more than 7 billion people live in urban environments—and by 2050, global population is projected to grow 25 percent, reaching over 9 billion people (United Nations World Water Assessment Programme 2016, 3). Yet, nearly half of the world's largest cities and 71 percent of global irrigated area are already in regions that experience at least periodic water shortages (Brauman et al. 2016). In the United States, 80 percent of states report that by the early 2020s, they expect water shortages even under nondrought "average" conditions (US General Accountability Office 2014). Nature has granted us a fixed freshwater budget; either we live within its limits, or we pay a high price for its lesser alternatives.
While many now cast their eyes to the vast oceans and the allure of desalination to solve the world's water supply problems, the brakes often slam hard on that dream when tallying up its formidable costs. The process of rendering ocean and brackish water into drinkable and usable water can cost 10 to 20 times more than that for freshwater development. And the financial costs of desalination may dim in comparison to its environmental burdens. Despite its abundance, desalting ocean water is far from free: vacuuming seawater into desalination plants destroys marine biota, generates large quantities of membrane filter solid waste, demands copious amounts of chemicals that become hazardous waste, and requires more energy than conventional water treatment plants. The controversial Carlsbad desalination plant in San Diego, California, cost over $1 billion to build (higher than its original budget) and comes with an annual $50 million electricity bill just to run the plant—all at a cost that will more than double the water bills of San Diego residents and businesses compared to what their nearby Southern California neighbors pay. Within its first year of operation, the Carlsbad plant racked up a dozen environmental violations for "chronic toxicity" for a chemical waste it was piping into the ocean. And for all that cost, the Carlsbad plant will only meet about 10 percent of the San Diego area's water demands—hardly enough to satisfy the many irrigated green lawns planted in that semiarid region—in a service area that has yet to maximize its water savings potential from conservation (Gorn 2016).
After more than a century of water supply development and accompanying exploitation of the natural ecosystems, the goal of quenching humanity's thirst for more water seems as elusive as ever. The severity and cost of the world's droughts and chronic water supply problems continue to worsen, in tandem with declining groundwater and surface water supplies. Yet, on every continent and in nearly every water system facing drought or long-term water shortage, an obvious but chronically neglected antidote has existed for more than a century: the minimization of water waste.
Year 1900: [I]t is evident that there must be a great amount of water wasted in many cities. Millions of dollars are being spent by many of our larger cities to so increase their supply that two-thirds of it may be wasted. This waste is either intentional, careless, or through ignorance. (Folwell 1900, 41)
Today: Estimates indicate that about 30% of global water abstraction is lost through leakage. (United Nations World Water Assessment Programme 2016, 12)
"Fix leaks," the most basic and oft-repeated admonition by water utilities to the public, is not always advice that they follow themselves. A study conducted by the American Water Works Association's Water Loss Control Committee of the real (leakage and other physical) losses in 11 water utilities found that they averaged 83 gallons/connection/day in 2015—an increase from the average 70 gallons/connection/day reported for those same systems in 2011 (Sayers et al. 2016). Given that US residential use averages about 88 gallons per capita per day (gpcd) (Maupin et al. 2014), the water lost through leakage in those 11 systems is nearly equivalent to the water demands of an additional person at every connection in their service area.
Avoidable and costly water waste—from leaking, neglected underground pipes to green lawns in deserts, and archaic flooding and inefficient sprinkler methods to grow food crops—remains so prevalent that it is typically considered normal if not inevitable. But is that a mindset we can continue to afford to guide drought response and water management today? To be sure, all water systems will have some leaks, humans need water for its functional value as well as its aesthetic and inspirational qualities, and beneficial reuse is a component of some irrigation losses. But to what extent have we defined our true water needs in contrast to our water wants, demands, and follies?
The contrast between water-tight systems and leaky ones is glaring, particularly in the face of reservoir-draining droughts and other water supply constraints. Cities such as Singapore and Lisbon report water losses of less than 10 percent, yet recently London has reported losses of 25 percent and Norway 32 percent (United Nations World Water Assessment Programme 2016, 25). Ongoing maintenance and repair of aging and leaking distribution water pipes and mains, many of which have a useful life of about 100 years before they need total replacement, is often a major source of avoidable system losses for water supply utilities. But too often suppliers neglect basic maintenance of their water infrastructure, and sometimes to an extreme. For example, Suez Water (formerly known as United Water), a private water company that serves over 300,000 residents in Rockland County, New York, for many years has reported its infrastructure leakage and other losses to exceed 20 percent. In one recent year, it was revealed that the "snail's pace" of Suez's main replacement program put it on an astonishing 704-year schedule, a clue as to why that system's high water losses have made it a source of public ridicule for so long. Despite its failure to implement an aggressive water loss recovery program (in tandem with New York state regulators who for years have flouted enforcement of their own water loss standards) to increase available supplies from its existing sources, for several years Suez, a player in the global desalination industry, has claimed that it "needs" to build a costly desalination plant on the Hudson River. Much to the consternation of water ratepayers and local officials who have challenged Suez's proposal, as well as the company's poor efforts at promoting conservation, the water demands of Rockland residents and businesses have been largely flat and under that system's safe yield since the early 2000s—hardly conditions that justify incurring public debt for a costly new water supply (Our Town News 2015, 6).
Despite declining domestic per capita water use in the United States (averaging about 88 gpcd, due in large part to national water efficiency standards for plumbing fixtures and appliances established first by the US Energy Policy Act of 1992 and in recent years by updated standards developed by the US Environmental Protection Agency's WaterSense and Energy Star programs [Vickers and Bracciano 2014]), not all Americans are using the national average amount of water. Excessive outdoor water use for lawn irrigation, much of it inefficient and too often leading to hardscape runoff and turf diseases, remains a vexing problem in countless US communities that doubles, triples, and sometimes quadruples average indoor winter demands. Does the average resident in Scottsdale, Arizona, really need to use three times more water than someone in Santa Fe, New Mexico, both desert communities that receive less than 15 inches of average annual rainfall? And how can water-scarce western US cities such as Henderson (Nevada), Denver and Fort Collins (Colorado), and Santa Barbara (California) seriously complain about water shortages and consider raising public debt for desalination and wastewater reclamation facilities when more than 50 percent of their single family home water use is seasonal, much of it typically devoted to lawn irrigation (Figure 13.1)?
Many point to the west and southwest regions of the United States for examples of excessive water use, such as the large volumes of water (over 50 percent of summertime demand in many places) devoted to residential lawn watering in large swatches of California, Nevada, Arizona, Colorado, and Texas cities and suburbs (Figure 13.1). Unfortunately, such practices are becoming more prevalent, including in regions such as precipitation-rich New England, and they are taking a toll. Such demands can tax the ecological balance of reservoirs, rivers, and aquifers even during times of normal precipitation, but they incur even more severe impacts during drought.
Although it is argued that raising water rates and sending a strong pricing signal about the value of water will curb abusive water use, some people,
Indicators of single family residential water use in the United States and Canada, average gallons per capita per day (gpcd). (From Maupin, M.A., et al., Estimated use of water in the United States in 2010, U.S. Geological Survey Circular 1405, 2014; Water Research Foundation, Residential end uses of water, Version 2, Water Research Foundation, Denver, CO, 2016; Vickers, A., Water efficiency and drought management practices: Comparison of national perspectives and local experiences, Annual Water Conference on Agricultural & Urban Water Use: Drought Management Practices, Water Efficiency, and Energy: sponsored by Southern California Edison, Tulare, CA, 2014.)
particularly the affluent, are price insensitive when it comes to wanting a perfect-looking green lawn. As Postel and Richter (2003, 176) pointed out more than a decade ago in Rivers for Life: Managing Water for People and Nature, "hefty water bills may not be enough: outright bans on lawn watering when river flows drop below ecological thresholds may be necessary" to preserve healthy streamflows and fish stocks.
Public officials and water managers typically remain stubbornly resistant to calls for mandatory lawn watering bans during droughts, opting for less effective voluntary approaches that may only shift but not reduce demand, even during the most severe conditions when water supplies can fall perilously low. And they are just as loath to admit the reason why they are averse to watering restrictions: excessive lawn irrigation may drain the town reservoir, but it fills the town coffers with revenues, especially during hot and dry weather.
Failure to take appropriate drought response actions early, in particular implementing mandatory cutbacks and bans on lawn watering, too often causes needless wildlife suffering and death. The official and media narrative on the damage and deaths associated with drought commonly distorts such losses as being caused by the drought, overlooking how officials were too little or too late in imposing restrictions on nonessential water demands. For example, in the major drought of 2016 that hit New England and the Ipswich River region of eastern Massachusetts most severely, the river reached historic lows and stopped flowing that summer. In its last gasp before drying up completely, the river's meager flows reversed course toward the town wells of North Reading and Wilmington, swallowed up in large part to sprinkle the last drops of Ipswich River water on nearby suburban lawns. As thousands of fish began dying while the Ipswich collapsed, the local Ipswich River Watershed Association declared it a "river in crisis" and implored officials to take aggressive conservation actions to save the river's flows (Ipswich River Watershed Association 2016). Yet, most of the water managers in the towns that draw water from the Ipswich waited until the river was completely dried up and the damage done, in late summer and after fish, turtles, and other wildlife were dead, to start imposing restrictions on outdoor water use. One local media outlet headlined the story as "Drought killing Ipswich River wildlife, forcing water restrictions across region" (MacNeill 2016). Did drought kill the wildlife, or was it the water managers and public officials who failed to impose watering restrictions early to keep the river flowing so that the wildlife could survive?
On the spectrum of water use, how wide is the stretch of inefficiency and waste? When we compute the simple equation that subtracts our true water needs from our total water demands, the sum—water waste and inefficiency— reveals an expansive "new" source of freshwater capacity that can not only relieve the effects of drought but also help offset the adverse impacts of longterm shortages.