This article is the second of a three-part series on water issues in
the Southwest. In the first part, we reviewed the primary ground and surface
resources available to our growing population. In this, the second, part, we
will examine the problems emerging from a dwindling supply, growing demand, and
long-term drought. In the third part, we will review potential long-term solutions
for our looming severe water shortages.
If
it's not a perfect storm, it'll do until one comes along.
Across the desert Southwest, our ground- and surface-water supplies are declining.
Simultaneously, our population and water demands are growing, and a long-term
drought – magnified by global warming – may well be under way. To
make things even worse, in some areas, vital underground and surface waters are
becoming polluted. Collectively, it all calls into question our paradigms of
how we should value and manage our water – that supremely important resource – in
coming years.
Critical Problems
Current or pending water shortages threaten the lands of our farmers (by
far the largest users of water); the homes, businesses and industries of our
communities; and the environmental health of our desert basins and mountain ranges.
Complicating matters, contamination may be rendering important water sources
totally unsalvageable in some areas. As one might expect, the shortage has prompted
struggles for sustainable clean water supplies among U. S. communities and states
and between the U. S. and Mexico.
Farmers
Our Southwest irrigation farmers – an economic force in
the region for centuries –cultivate some 2.5 million acres of land, including
about 2.25 million acres in the lower Colorado River Basin and 0.25 million acres
in the upper Rio Grande Basin, according to data in the U. S. Geological Survey
report "Water-Use Trends in the Desert Southwest—1950-2000," by
A. D. Konieczki and J. A. Heilman, and our farmers are now facing major change
that will emerge from looming water shortages.
While producing vitally important foods, fibers and livestock feeds, the farmers
use several times more water than all municipal, domestic and industrial users
combined. Under most current irrigation practices, a farmer often uses several
acre feet of water per acre per year in his fields. (An acre-foot of water – that
is, enough water to cover an acre of land to a depth of one foot – comprises
about 326,000 gallons, enough to meet the household needs of a typical family
of four for a year or more.) Only a small fraction of the irrigation water actually
benefits his crops or recharges the natural aquifers. The balance escapes from
irrigation channels or evaporates into the sky. (In the northern Chihuahuan Desert,
annual average rainfall equals less than nine inches. Annual average evaporation
rates equal more than nine feet.)
Oftentimes, the farmers' income from their crops may only barely exceed the
value of the irrigation water they use. For example, as Robert Kunzig said in
a recent issue of National Geographic magazine, compared with the price that
San Diego has paid recently for water ($300 per acre-foot), "…the
irrigation water in the Imperial Valley [in southeastern California] is worth
nearly as much as its entire agricultural revenue, which is around a billion
dollars a year." While owners of large farms might benefit from selling
their water to municipalities rather than using it for irrigating crops, "Many
more people fear the loss of jobs and, ultimately, of a whole way of life."
More than 20 years ago, in Western Water Made Simple, Ed Marston made the
dire prediction that, "Agriculture is slated to die. Even in the productive
Arizona and California valleys, irrigated agriculture is seen as a stopgap: a
100-year-long activity that will be bought out or forced out by urbanization."
While Marston probably overstated his case, the farmers of the desert
Southwest face the increasingly urgent requirement to capitalize on more efficient
(and undoubtedly more expensive) technology for irrigating their crops.
Communities
Municipal water managers have become acutely aware of the dilemmas raised
by increasingly short water supplies available to their communities.
"…we're not running out of water, we're running out of inexpensive
water," Ed Archuleta, Director of El Paso Water Utilities, told David Ogden-Tamez, "Water:
A Growing Concern in The Border's Desert Communities," published on the
New Mexico State University Internet site. Archuleta probably summed up the problem
for many communities across the desert Southwest.
"…municipal water conservation programs are required" in
central and southern Arizona "and new residential developments for which
there is not a 100-year assured water supply from primarily non-groundwater sources
are not allowed," Roger Manning, executive director for the Arizona Municipal
Water Users Association, told the Environment News Service Internet site, "Global
Warming Brings Perpetual Drought to the U. S. Southwest."
"We're the canary in the mine shaft," Patricia Mulroy, general
manager, Southern Nevada Water Authority told Sunset magazine, March 2008. "When
I look at the Colorado River, I know that by 2010, Hoover Dam could potentially
not generate electricity. That Lake Mead is down—90 percent of Las Vegas'
drinking water comes from there. What do you do?"
"Ground zero is right here in Las Vegas," Scott Huntley, spokesman
for the Las Vegas Valley Water District, told the Environment New Service Internet
site.
Confronting intensifying shortages, cities across the Southwest have moved
to curtail water use and to tap new sources. Some have set higher water-saving
standards and regulations for new domestic and commercial plumbing and fittings,
offer economic incentives for retrofitting old plumbing and fittings, promote
use of water-saving technology, restrict watering of lawns, encourage planting
of desert-adapted vegetation, buy water rights from farmers and ranchers, and
offer programs to educate the public. Increasingly, communities have begun using "gray" water – treated
sewage water – to cool industrial plants and irrigate public lands such
as golf courses and parks. A few, for instance, El Paso, Texas, and Alamogordo,
New Mexico, have built new treatment plants for purifying mineral-laden ground
waters. Others, like Las Vegas, are contemplating reaching out, laying pipelines
for hundreds of miles across the desert, to connect them to distant water sources.
The cities' efforts have produced some results. From 2002 to 2006, the Las
Vegas metropolitan area – at the epicenter of the shortage – was
actually able, said Kunzig, "to reduce its total consumption of water by
around 20 percent, even though its population had increased substantially." Nevertheless, "…every
water manager also knows that, as one puts it, 'at some point, growth is going
to catch up to you.'" Most Southwest communities still have to deal with
difficult choices and formidable challenges in developing long-term sustainable
water supplies.
Environment
Our Southwest environment reflects the heavy burden imposed by the overuse
of ground and surface waters—in the desert basin ground surfaces above
the aquifers, the riverine environments along the stream drainages, the wooded
slopes of the mountain ranges, and water sources with significant domestic and
industrial contamination.
"As water levels in the aquifers decline," said the U. S. Geological
Survey in "Desert Basins of the Southwest," Science
for a Changing World Internet site, "the slow drainage from the clay and silt layers cause
them to compact, and the land surface to be lowered." West of Phoenix,
for instance, the surface has subsided some 18 feet. At Eloy, Arizona, it has
subsided 15 feet. Near Mendota, in central California, it has subsided 29 feet!
The land surface can tilt and crack, setting the stage for damage to "buildings,
pipelines, canals, drainage ditches, roads, railroads, dams, and bridges."
Along the Colorado River, impoundments have permanently changed the aquatic
ecosystem, according to the Land Use History of North America,
Colorado, Plateau, Internet site, "Endangered Fish on the Colorado Plateau." The impoundments "have
drastically changed water temperature, converted the river from [nutrient-rich]
sediment-laden to relatively clear, altered historical patterns of spring floods
and the general water-flow regime, and blocked migratory pathways for fishes." This,
combined with drainage of aquifers and consequent loss of springs, means that "fishes
in the western United States are clearly more imperiled than those in the eastern
United States."
At the Colorado River's mouth, at the northern end of the Gulf of California,
the 1.9-million acre riparian habitat currently "hangs by a thread," according
to the Environmental Defense Fund's Internet site. It began drying up in the
1930s, when the river's waters were diverted to irrigate fields and supply communities.
It now receives less than one-tenth of one percent of all the water in the river
system. CounterPunch Newsletter said in March of 2001, that the "estuary
used to be one of the wonders of the world; a vast wetland, teeming with more
than 400 species of plants and animals." It is now little more than "a
salt flat."
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