Department of Water Resources
A daily compilation for DWR personnel of significant news articles and comment
February 13, 2008
1. Top Items
Experts warns Lake Mead could be dry by 2021 - Associated Press
Reservoirs could dry out by 2021; Colorado River crisis looming, report says - San Diego Union Tribune
Scientists: Mead, Powell dry by 2021; Water officials dispute Scripps' Colorado River study - North
Lake Mead could run dry by 2021, study warns - Arizona Republic
Experts warns
Associated Press – 2/13/08
Researchers at
There is a 50 percent chance
"We were stunned at the magnitude of the problem and how fast it was coming at us," said marine physicist Tim Barnett. "Make no mistake, this water problem is not a scientific abstraction but rather one that will impact each and every one of us that live in the Southwest."
Currently, Lake Mead - located in
Researchers said that if Lake Mead water levels drop below 1,000 feet,
http://www.sbsun.com/search/ci_8249429?IADID=Search-www.sbsun.com-www.sbsun.com
Reservoirs could dry out by 2021;
By Mike Lee, staff writer and Michael Gardner, Copley News Service
That would jolt
Major industries – from tourism to biotech – would be affected by such a shortage, which already is starting to force changes. A large marina on
This latest warning could escalate pressure for more conservation, either voluntary or mandatory, several water experts suggest.
The report is the first in a peer-reviewed journal to pin a date on when the river's water level would drop so low that reservoir water could no longer be drawn by gravity, said authors Tim Barnett and David Pierce, scientists at Scripps, which is part of the
“We were stunned at the magnitude of the problem and how fast it was coming at us,” Barnett said. “Make no mistake, this water problem is not a scientific abstraction, but rather one that will impact each and every one of us that live in the Southwest.”
Several other reports in recent years agree that the
“Based on the assumptions that (Barnett and Pierce) made, I certainly don't disagree with this conclusion,” said Terry Fulp, operations manager of the
Fulp added a caveat: Long-term changes in river flows can't be predicted precisely, so the Scripps calculation could be off by several years.
The Lake Mead-Lake Powell system includes the stretch of the Colorado River in northern
“It's pretty dramatic. ... From month to month, there is a noticeably bigger white band (of rock and sand) and you can see more islands popping out of the water,” said Krystyna Stave, an environmental studies professor at the
On a positive note, snowfall along the river system has been recorded at 128 percent of normal this year, which will add 3.5 million acre-feet to
Pierce and Barnett approached future river flows based on probability of certain events. They gave a 10 percent chance that functional storage in Mead and Powell reservoirs will be gone by 2013 and a 50 percent chance that it will disappear by 2021. They said there's a 50 percent chance that the minimum power-production levels in both lakes will be reached in 2017, based on current trends.
Martin Hoerling, a meteorologist for the National Oceanic and Atmospheric Administration in
The Scripps report “should catch attention because climate change is real and it needs to be part of the dialogue about how we manage the water resources,” Hoerling said.
Barnett and Pierce touched on possible solutions, many of which already are being tried across the region. Those include increased calls for conservation, new guidelines for managing river water and numerous attempts to tap potential supplies such as the
“We are all planning to deal with less water from the
Concerns on the Colorado River have been heightened by legal complications to moving water from Southern California's other major water source, the Sacramento-San Joaquin River Delta. This year, the region's farmers have had supplies cut by 30 percent.
Despite problems, numbers released yesterday by the San Diego County Water Authority show that the county set a record high for water use in 2007.
While per-capita use has remained relatively flat over the past two decades, the growing population keeps nudging the total demand up.
Several water managers in
“The public isn't believing that we have as much of a constraint as we really do. . . . They turn on the tap and there is plenty there,” said Bud Irvin, board president of the Santa Fe Irrigation District in
The county water authority mainly has relied on stories in local media and word of mouth to spread the conservation message. But it's working on a plan that's likely to include a big increase in paid advertising. No budget has been proposed.
Jim Barrett, director of public utilities for the city of
“We don't want to excite people needlessly in anticipation there might be a problem later,” Barrett said.
Rationing would be difficult to fairly impose, he said, because an across-the-board reduction would punish households and businesses that have already started to save.
“There are folks who aren't paying attention to water conservation,” Barrett said. “They're trying to replicate an Amazon rain forest in their backyard.”
But with snowfall unreliable, reservoir levels dropping and environmental problems tightening deliveries through the Sacramento Delta, water managers are under increasing pressure to conserve more even as
Gary Bobker, program director for the Bay Institute of San Francisco, an environmental advocacy group, said the state must explore rationing as climate change threatens to reduce snowpack.
“All over the state, we should be moving toward mandatory conservation because it's the right thing to do. Water is a finite resource,” he said.
Bobker suggests that the large water sellers, such as the San Diego County Water Authority, establish mandatory reduction targets and then allow their customers to decide how to best achieve those savings.
“We need to start preparing now,” he said. “We have some time, but we're going to run out of time.”
Ronnie Cohen, senior policy analyst with the Natural Resources Defense Council, said “it's time for a new approach” – including pushing the Department of Water Resources to set statewide savings goals.
“As a state, we need to figure out what level of water use is sustainable and then develop a plan to get there,” she said.
In another attempt to manage potential shortages, the Metropolitan Water District yesterday approved a controversial rationing plan for most of
However, Metropolitan may be able to avoid using it this year because of healthy winter storms. A decision on whether to impose rationing won't be made until May.
The strategy calls for an across-the-board cut for all of Metropolitan's member-agencies, depending on water conditions.
The San Diego County Water Authority would lose anywhere from 65,000 acre-feet to nearly 190,000 acre-feet, based on a complex set of factors.
An acre-foot is 326,000 gallons, or enough to serve two average households for a year.
“We're trying to work the best possible solution for the region,” said Barrett,
http://www.signonsandiego.com/news/metro/20080213-9999-1n13mead.html
Scientists: Mead, Powell dry by 2021; Water officials dispute Scripps'
By Gig Conaughton, staff writer
Their dire predictions were immediately challenged by federal and local water officials.
Researchers Tim Barnett and David Pierce said there was a 50-50 chance that the reservoirs will be dry by 2021 --- but that they were not predicting that would actually happen.
Instead, Barnett said, the report predicted only that the chance the lakes will run dry by 2021 could be reduced to a coin flip -- one chance in two -- because people were using too much of the Colorado River's water and global warming was eating away the southwest United State's "normal" precipitation.
Officials from the federal Bureau of Reclamation that manages the
The agency's regional director, Terrence Fulp, said the agency's own studies predicted that Mead and Powell would be a little less than half full in 2021 -- levels that would provide enough water to supply California, Nevada and Arizona for two years even if the river stopped flowing.
Meanwhile, water officials in
They also said the
"Right now we're sitting on the best snowpack in 11 years -- 128 percent of normal," said Roger Patterson, assistant manager of the Metropolitan Water District, Southern California's main water supplier and the agency that built the
However, Barnett, a geophysicist, said the Scripps study looked past today's conditions and into the long-term reliability of the Colorado River, which has been the key water supply of the populations and economies of Southern California,
Barnett said federal statistics show that
That, he said, eats into Mead and Powell's storage. An acre-foot is enough water to sustain two households for a single year. Barnett said there was 13 million acre-feet of water in Powell and Mead as of July 2007, and that if people continued to overuse the river by 1 million acre feet a year, the reservoirs would be empty in 13 years -- 2021.
Barnett said that if Mead and Powell ran dry, it would cut hydroelectric production important to the entire West, and make the Colorado River's supplies "highly unstable" because they would be based on year-to-year flows, not stored supplies. Barnett said the Scripps report relied on a
"You have to wonder if the civilization we've built in the desert Southwest is sustainable in the future," Barnett said.
Patterson, however, said the Scripps study was based on the idea of a continual decline and did not consider that the
He said the current snowpack could mean that there would be 3.5 million more acre-feet in the river -- even after
"If we have back-to-back years like that, we're back in a surplus condition," Patterson said, meaning that Powell and Mead would be largely restocked.
Patterson and Ken Weinberg, the water resources manager of the San Diego County Water Authority, said that water agencies were taking steps to cut water use.
"No one is planning to continue to use the river the same way they have been historically," Weinberg said.
He said an illustration of that effort came in December, when
http://www.nctimes.com/articles/2008/02/13/news/top_stories/8_31_332_12_08.txt
Lake Mead could run dry by 2021, study warns
By Shaun McKinnon, staff writer
Climate change and an unquenched demand for water on the Colorado River could drain
The scientists, working at the Scripps Institution of Oceanography in
If drought deepens and water use climbs, the researchers said there is a 50 percent chance
"We were stunned at the magnitude of the problem and how fast it was coming at us," said marine physicist Tim Barnett, who co-authored a paper examining the fate of
Barnett and co-researcher David Pierce, a climate scientist, said they used conservative estimates in reaching their conclusions and suggested even more dire conditions are possible. Their findings will appear in the journal Water Resources Research, published by the American Geophysical Union.
Lake Mead and its upstream sibling, Lake Powell, help manage water resources for more than 25 million people in the seven states, including Arizona, that rely on the Colorado River for water and power.
The two huge reservoirs have been the subject of numerous hydrology models in recent years, but none forecast a dry
"We did a lot of studies, and none of them ever made
"We did what we called our worst case, and it just didn't happen," he said.
Dozier was part of the team that helped produce water guidelines adopted in December by the seven river states. The guidelines detail how water should be allocated among the states in times of shortages and were based in large part on water levels in the two reservoirs, which control most of the river's storage.
Some of the scenarios predict shortages within the guidelines as early as 2010, but they were triggered by low water levels, not empty reservoirs.
But Barnett and Pierce said the new guidelines would not protect water users in the worst-case scenarios envisioned by their study, which analyzed water use and the expected effects of climate change.
"When expected changes due to global warming are included as well, currently scheduled depletions are simply not sustainable," the researchers wrote in the paper.
If Lake Mead emptied,
Power production also would cease before the lake level reached bottom.
Lake Mead is currently half-full, as is
http://www.azcentral.com/arizonarepublic/news/articles/0213lakemead01213.html
New York Times – 2/13/08
By Felicity Barringer, staff writer
Lake Mead, the vast reservoir for the Colorado River water that sustains the fast-growing cities of
The lake, located in Nevada and Arizona, has a 50 percent chance of becoming unusable by 2021, the scientists say, if the demand for water remains unchanged and if human-induced climate change follows climate scientists’ moderate forecasts, resulting in a reduction in average river flows.
Demand for
“We were really sort of stunned,” Professor Barnett said in an interview. “We didn’t expect such a big problem basically right on our front doorstep. We thought there’d be more time.”
He added, “You think of what the implications are, and it’s pretty scary.”
The two researchers used data on river flows and reservoir levels from the federal Bureau of Reclamation, the agency that manages the lower Colorado River and the reservoirs of Lake Mead and
Other recent research has shown that the watershed feeding the
The agreement, including measures to encourage conservation, was expected to forestall litigation among various claimants for the water. It was based on an assumption that the current flow measured at Lee’s Ferry, just south of
The Scripps study indicates that the odds are that the shortfall will exceed 500,000 acre-feet a year long before 2026, when the new agreement runs out. The study has been accepted for publication in Water Resources Research, a journal of the American Geophysical Union.
Pat Mulroy, the general manager of the Southern Nevada Water Authority, said that she had not read the study but that the agreement the states and federal government reached last year included provisions to reconvene if the water losses went beyond what they originally envisioned.
“We have to protect our communities against the worst possibility,” Ms. Mulroy said. “We have 90 percent of our water supply coming from
Among the plans being pursued, she said, are conservation (“We’ve started down this journey to make a cultural transformation in this community where water isn’t something they take for granted”) and a design for a project to find a rechargeable groundwater supply unconnected to the
In connection with the agreement, the Bureau of Reclamation released an extensive environmental analysis of water flows and storage in the lower
In the executive summary of the bureau’s analysis, the authors wrote that global climate change models could not be scaled to local effects. The report used more than 1,200 years of tree-ring data to determine the historical record of river flows.
“Based on the current inability to precisely project future impacts of climate change to runoff throughout the
The question of scaling global models to regions and subregions has troubled many climate scientists. Professor Barnett, when asked about the reliability of projecting such models on the
“There is concern about the representativeness of it,” he said.
But, he added, he and a colleague recently published a separate study that looked at how well climate models predicted
He added, “I don’t mean to call it a doom-and-gloom scenario, but it’s got a little hint of that.” #
http://www.nytimes.com/2008/02/13/us/13mead.html?_r=1&ref=us&oref=slogin
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