I chatter, chatter, as I flow
To join the brimming river,
For men may come and men may go,
But I go on for ever.
Maybe Not
Last year, for the first time, the amount of water
transferred from Lake Powell to Lake Mead was reduced, by enough to supply
about 1.5m homes. If the snowpack on the Rockies is as bad as Davis fears, then
there is likely to be a deeper cut in the coming months under a series of
agreements which allocate water rights.
The original agreement,
the Colorado
River Compact, carved out nearly a century ago, divides the river’s
water between the states that rely on it. With hindsight, it sowed the seeds of
some of today’s problems. It failed to foresee the rapid rise in population in
the desert states of Nevada and Arizona, and the demands of their cities and
farms. Nevada, for instance, was allocated only 2% of total of the water
distribution.
The compact was also premised on predictions of snow packs
on the Rockies which some environmentalists have concluded were based on a
period of abnormally high rains in the west during the first quarter of the
20th century.
The agreement gives some states greater claim than others
when the water runs short.
Arizona loses
out, except for a county next to the Mexican border which has what are
known as “senior rights” because it produces much of the US vegetable crop in
winter.
Nevada
also does badly.
The big winner is
California, which gets to keep its much larger allocation, for a while, at
least.
That state of affairs can be traced back nearly half a
century to construction of the largest aqueduct system in the US to deliver the
Colorado’s water to central and southern Arizona. The canals of the Central
Arizona Project (CAP) provide water to cities such as Tucson and Phoenix, and
irrigate close to 400,000 hectares (1m acres) of farmland. Without it, Arizona
would be less fertile and, probably, less inhabited.
But the CAP required the support of California’s members of
Congress to win funding and they exacted a price – if the water is rationed,
Arizona’s allocation is cut by half before California takes any hit at all.
In 2007, seven years into the present drought, new
allocations were signed by the US secretary of the interior in case the water
shortages grew. The cutbacks to the states kicks in if Lake Mead falls below
1,075ft.
In April of this year it was just 4ft short of that
benchmark as it fell to its lowest level since 1937, when the lake was still
being filled. If the water levels continue to drop, Arizona and Nevada will
face immediate cuts, escalating as the lake falls further.
That would threaten cities such as Las Vegas and the very
existence farms fed by the Arizona aqueduct. If the lake sinks below 1,000ft,
the water intake pipes would start sucking air. The Hoover Dam power turbines
would also stop spinning, interrupting an important source of electricity to
the region.
Davis said it’s a prospect that kicked state governments
into gear.
“We signed these guidelines in 2007, so all of the states
have been very proactive in storing groundwater, implementing conservation
measures, using recycling technologies. They have seen this coming,” she said.
Nevada is recycling most of the water used by residents and
tourists in Las Vegas. The Southern Nevada
Water Authority put in
place a conservation plan that includes limiting the size of lawns,
restrictions on watering gardens and campaigns to shorten the time spent in showers
or running dishwashers. The authority says it has reduced demand from about 314
gallons per person per day in 2002 to about 205 gallons per day last year, and
saved 32bn gallons of water despite the region’s population rising by more than
500,000 people.
How the west was lost
The Colorado River Basin is the water lifeline of the
western United States. It provides water to roughly 40 million people in
7 states and to Mexico. It supplies water to major metropolitan
regions including several of the country’s largest and driest — Los Angeles,
San Diego, Phoenix and Las Vegas — and enough water to support irrigation on 4
million acres of farmland. As the water future of the Colorado River
Basin goes, so does that of the west.
In our new study, we used
NASA satellites to find
that between December 2004 and November 2013, the Colorado River Basin lost a
total of 65 cubic kilometers of water, or roughly the equivalent of two full
Lake Meads. This was a period of prolonged drought in which the water
levels in Lake Mead and Lake Powell (the United States’ second largest
reservoir) had fallen to dangerously low levels, and were being carefully
managed to prevent further declines. Surprisingly, we found that 75% of the
water lost was from the Basin’s groundwater supplies.
http://voices.nationalgeographic.com/2014/07/24/how-the-west-was-lost/
Streamflow of the Colorado River Basin is the most
overallocated in the world. Recent assessment indicates that demand for this
renewable resource will soon outstrip supply, suggesting that limited
groundwater reserves will play an increasingly important role in meeting future
water needs. Here we analyze 9 years (December 2004 to November 2013) of
observations from the NASA Gravity Recovery and Climate Experiment mission and
find that during this period of sustained drought, groundwater accounted for
50.1 km3 of the total 64.8 km3 of freshwater loss. The rapid rate of depletion
of groundwater storage (−5.6 ± 0.4 km3 yr−1) far exceeded the rate of depletion
of Lake Powell and Lake Mead. Results indicate that groundwater may comprise a
far greater fraction of Basin water use than previously recognized, in particular
during drought, and that its disappearance may threaten the long-term ability
to meet future allocations to the seven Basin states.
- Research Letter, “Groundwater
depletion during drought threatens future water security of the Colorado River
Basin. Authors:
Stephanie L. Castle,
Close author
notes
UC Center for Hydrologic Modeling,
University of California, Irvine, California, USA
Department of Earth System Science,
University of California, Irvine, California, USA
UC Center for Hydrologic Modeling,
University of California, Irvine, California, USA
Department of Earth System Science,
University of California, Irvine, California, USA
NASA Jet Propulsion Laboratory,
California Institute of Technology, Pasadena, California, USA
UC Center for Hydrologic Modeling,
University of California, Irvine, California, USA
Department of Earth System Science,
University of California, Irvine, California, USA
NASA Jet Propulsion Laboratory,
California Institute of Technology, Pasadena, California, USA
Hydrological Sciences Laboratory,
NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
Climate and Global Dynamics Division,
National Center for Atmospheric Research, Boulder, Colorado, USA
UC Center for Hydrologic Modeling,
University of California, Irvine, California, USA
Department of Earth System Science,
University of California, Irvine, California, USA
NASA Jet Propulsion Laboratory,
California Institute of Technology, Pasadena, California, USA
First published: 29 August 2014Full
publication history
No wait. It got harder. I went
grocery shopping. One thing always on my list is “dinner”. The original concept
for using this ambiguous word was to find something inspiring and fresh in
produce and get creative. Lately, it has been trying to find the latest trend
in pre-made dinners: fully cooked but fresh dinners. You could take them home
and freeze them, or you could take them home and put them on a plate and feel
like you were slightly more righteous than eating microwaved organic pencil
shavings labeled non-GMO and/or gluten-free. Eventually, it’s Mrs. Paul’s Fish
Cakes with that mutant condiment son of mayonnaise and chopped pickles: tartar
sauce. Just as long to nuke as a handful of frozen Tater Tots on the same plate.
