Day of reckoning for the parched Southwest: technology and conservation won’t be enough

Feb. 19, 2014 — When it comes to water in America, this truth is self-evident: We are guzzlers from sea to shining sea. Nowhere, though, are the effects of our thirst as visible and self-destructive as they are in the Southwest, the fastest-growing and driest region of the country, where just one long and lonely river, the Colorado, must slake the needs of seven states.

Lake Powell, the huge reservoir that straddles the border of Arizona and Utah, has lost half of its water since 1999 because of drought and human water use. The drop in water levels is evidenced by the pale pink “bathtub rings” along the canyon’s iconic sandstone walls.

The 1,450-mile river, once broad and blue, has in many places shriveled to a muddy trickle. On the Arizona-Nevada line, Lake Mead, our biggest reservoir and a crucial water source for cities from Las Vegas to Los Angeles, sits below half-capacity, as does its sister lake, Powell. In New Mexico, Arizona, and southern California, the earth is fissuring and subsiding in spots – picture sinkholes in Florida – because aquifers are excessively drained. And from California to Colorado to Wyoming, farmers are bulldozing orchards, fallowing alfalfa fields, and unloading herds of cattle because soil moisture is so low.

Atop the Rocky Mountains, another warning sign: dust-darkened snow, tinged the color of cinnamon. Increasingly vehement windstorms – haboobs, as some locals refer to them – are depositing more and more desert dust and sand on the peaks, which does more than gum up slopes for skiers: The dark film hastens absorption of sunlight, thereby melting snow faster and speeding runoff, a problem for farmers and water managers who rely on slowly thawing snow packs to deliver water downstream in regular volumes year-round.

It’s not seriously disputed that the region’s water shortfall is large and will become worse, even in the absence of drought. Likewise, it is widely acknowledged that increasingly strict conservation measures will soon become the norm in the region. What is striking, however, is the reluctance of state officials, builders, and others to acknowledge two more truths that the weight of evidence points to: first, that the relentless growth the Southwest has become accustomed to over the last half-century is unsustainable; second, that either in a planned way executed over time to cushion shock or disruptively after more years of whistling past the graveyard, growth of population and industry will slow and stop.

As of now, no one in a position of authority appears to be giving any thought to what a non-growth environment would look like and how it could be managed.

There’s no light at the end of this tunnel

A 2012 report by the U.S. Bureau of Reclamation included a remarkably ominous projection: By 2060, it said, water demand in the Colorado River Basin states of Wyoming, Colorado, Utah, New Mexico, Nevada, Arizona, and California is likely to outstrip supply by more than 10 times what Las Vegas uses each year. Meanwhile, a spate of climate-change studies by the National Academy of Sciences shows that rising global temperatures will diminish the Colorado’s average flow after 2050 by 5 to 35 percent. Those projections are premised on rainfall levels remaining the same as they are now; most models predict drier years ahead, not wetter ones.

Were nothing done to change our current trajectory, Remapping Debate asked Carly Jerla, a hydrologic engineer with the Reclamation Bureau and a co-manager of its 2012 Basin study, how would a water emergency play out by, say, 2050?

Could dropping water levels cause hydroelectric dams like the Hoover and Glen Canyon to churn out significantly less energy or stop altogether? (Possibly.) Could aqueducts that serve the cities of Phoenix, Tucson, San Diego and Los Angeles – not to mention the factory farms of California’s Imperial and Coachella valleys – start drying up? (Possibly.) Could America’s playground, Las Vegas, actually have to ration water? (Again: possibly.)

The obvious expedient of cutting back on water consumption is already happening, albeit in a patchwork manner. Water-saving efficiencies in the home (the unfortunately phrased “toilet-to-tap” solutions) are what allow Las Vegas officials to boast that everybody can take 20-minute showers every day without raising the city’s consumption a drop. In southern California, the metropolitan water district gives away high-efficiency water nozzles and subsidizes artificial turf and zero-water urinals. The Palo Verde nuclear station just west of Phoenix is the only nuclear power plant to use reclaimed wastewater for cooling. Prescott Valley, Arizona, whose population has ballooned 50 percent since 2000, irrigates golf courses with treated wastewater and sells permits to its future supply of treated effluent to developers who need to show they have a proven, 100-year source of water before they can build new homes. On the farm, growers are flattening fields with lasers to reduce runoff. Others are turning to water-efficient drip and microsprinkler systems and gizmos with names like “AquaSpy,” sensors planted at a crop’s root zones to monitor soil moisture in real time, to reduce water use and increase yields.

But conservation isn’t bringing water use into balance with available supply – the water deficit remains. Take Arizona, often lauded for its water-saving efforts. Since 1980, the state has had a groundwater management act that, in theory, permits residential construction only if builders can demonstrate the existence of a 100-year water supply and show how they will “recharge” what future homeowners draw from local aquifers. That program is what Spencer Kamps, a spokesman for the Home Builders Association of Central Arizona, pointed to when he told Remapping Debate, “We’re in a sustainable model for many years … We don’t have a water problem in Arizona.”

Yet Arizona’s Department of Water Resources released a report last month, “A Strategic Vision for Water Supply Sustainability,” which concluded: “Although the State has an existing solid water management foundation, water demands driven by future economic development are anticipated to outstrip existing supplies.”

By how much? “When we looked at some of the studies that were done for Arizona,” says Sandra Fabritz-Whitney, the department’s director, “what we found is our imbalance in a hundred years could be 3 million acre-feet” – in other words, roughly the same deficit that the U.S. Bureau of Reclamation projects for all seven Basin states by 2060.