For 14 years, a huge desalination plant has
sat quietly, out of operation, on the banks of the Colorado River
just north of the Arizona border. And just south of the border, the
Cienega de Santa Clara, a manmade wetland of over 14,000 acres, has
provided critical habitat for migrating birds.
The
wetland and the desalination plant are intimately connected — the
wetland is nourished by the same water supply that was supposed to
feed the plant — and until recently, it seemed they would not be
able to coexist.
In other arid Western regions, water
projects have improved efficiency but left environmentalists
scrambling to find new sources of water for drying marshes and
lagoons (see our story The
Efficiency Paradox). But when the Yuma plant shuddered to
life this March for a test run, water managers, environmental
groups and federal officials were confident the Cienega de Santa
Clara would survive, thanks to some proactive planning.
The wetland owes its size to an international treaty requiring that
1.5 million acre-feet of Colorado River water arrive in Mexico each
year. In the 1960s, Mexican farmers began complaining that salty
water from the river was damaging their crops. The high salinity
levels violated treaty requirements, and agricultural runoff from
an irrigation district near Yuma turned out to be the culprit. In
the 1970s, the salty runoff was diverted into the Cienega, which
grew from its original 450 acres to today’s size.
The diversion was supposed to be temporary until a desalination
plant could be built. But the plant, which was finished in 1992,
never operated apart from a nine-month test run. The next year,
flooding eliminated the need for plant operations. By the time
water levels returned to normal, the Cienega was already a huge
wetland, providing forage for birds on the Pacific Flyway and
housing federally protected species like the Yuma clapper rail,
southwestern willow flycatcher and a desert pupfish. The plant,
with its high operating costs, remained closed (see our story Draining
the budget to de-salt the Colorado).
Now, eight
years into a drought, water managers are looking at ways to squeeze
more water out of the river. The Central Arizona Project, which
manages water for three Arizona counties, suggested reopening the
desalination plant so that some of the salty water going into the
Cienega could be cleaned and sent to Mexico; that would allow more
water to be used upstream. However, redirecting the water feeding
the Cienega could have dried up the huge wetland and resulted in
environmental lawsuits. To avoid that scenario, Sid Wilson, general
manager of the Central Arizona Project, brought together officials
from the Bureau of Reclamation, environmental groups and water
managers to hash out a solution.
The result is a
three-month test period with the Yuma desalination plant operating
at 10 percent capacity. The Central Arizona Project is paying for
monitoring of the Cienega to ensure the wetlands are not harmed.
“Our goal is to get the Yuma desalination plant up and
running,” says Bob Barrett, spokesman for the Central Arizona
Project, “but we’re not taking that tack at the expense
of the environment.”
After the trial ends in
mid-May, group members will decide what to do next, based on the
efficiency and cost of plant operations. Jim Cherry, area manager
for the Yuma office of the Bureau of Reclamation, says there are no
plans to run the plant at full capacity yet. In determining the
future of the plant, Barrett highlights the ongoing cooperation of
the group, something that is, he says, “a revolution to the
water world.”
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