Study: Colorado River water supply safe through 2026

Researchers say climate change, river management pose greatest threat

SAM MORRIS / LAS VEGAS SUN file

A seven-state agreement signed 80 years ago gives Nevada 300,000 acre-feet of water each year from the Colorado River.

Wednesday, July 22, 2009 | 1:41 p.m.

Lake Mead marinas buy time to move to deeper water (6-26-2009)
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Report: Rivers serving most people, like Colorado, drop as climate changes (4-21-2009)
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Using less water — but why? (2-13-2009)
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Satiating a booming city (6-1-2008)
Water: The more you use, the more you’ll have to pay (4-8-2008)

For Want of Water: Find video reports, interactive graphics and expanded coverage of Las Vegas' water shortage

There's a bit of good news in a new study of warmer climate conditions along the Colorado River, especially when it comes to Lakes Mead and Powell.

There's enough water currently stored in the river, especially in the two largest man-made reservoirs of Lake Mead and Lake Powell, that the chances of draining the Colorado's delivery system are slim through 2026. That's a few years later than some other projections.

Even under the most extended drought possible, threats to the river supplying water to roughly 30 million people in California, Nevada and Arizona won't be felt soon, said Balaji Rajagopalan, lead author on the study from the University of Colorado.

"There's a tremendous storage capacity on the Colorado River that helps with the reliability of supply over periods of a just few years," Rajagopalan said.

Lakes Mead and Powell can store up to 50 million acre feet of water alone, he said, which is the vast majority of the 60 million acre feet that can be stored in the entire Colorado River.

As a result, the risk of draining the reservoirs remains low through 2026, even with a 20 percent stream flow drop from climate change.

But between 2026 and 2057, current river management practices will pose a greater threat to the lakes becoming dry than increasing population pressures, Rajagopalan said.

"On average, drying caused by climate change would increase the risk of fully depleting reservoir storage by nearly 10 times more than the risk we expect from population pressures alone," Rajagopalan said. "By mid-century this risk translates into a 50 percent chance in any given year of empty reservoirs, an enormous risk and huge water management challenge."

The Colorado River is enduring its 10th year in a drought that began in 2000, the study says.

Fortunately, the river entered the drought with its reservoirs at about 95 percent full. The reservoirs have 59 percent capacity left -- about the same amount as last year, Rajagopalan said.

Water managers should re-think current water management practices before more serious effects of climate change appear, Rajagopalan said.

The severity of the risk depends on the extent of climate drying and on the types of water management and conservation measures established, the study says.

By combining water conservation and small pre-planned delivery shortages tied to dropping reservoir levels, the risk of draining the lakes dry can be reduced, said Ken Nowak, a graduate student who participated in the study and is one of its authors.

"But the more severe the drying with climate change, the more likely we will see shortages and perhaps empty reservoirs despite our best efforts," Nowak said. "The important thing is not to get lulled into a sense of safety or security with the near-term resiliency of the Colorado River basin water supply. If we do, we're in for a rude awakening."

The study is in press in the American Geophysical Union journal, Water Resources Research.

Discussion: 13 comments so far…

By NucEngineer

7/22/09 at 1:57 p.m.

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There has been atmospheric cooling the last 8 years, and no new high global annual temperatures in the last 11 years. None of the computer models replicate this fact. Anthropogenic (or man caused) global warming is not proved.

The global warming adherents base their argument of proof on more than 20 different computer models called general circulation models (also known as global climate models or GCMs). Each computer model is composed of dozens of mathematical equations representing known scientific laws, theories, and hypotheses. Each equation has one or more constants. The constants associated with known laws are very well defined. The constants associated with known theories are generally accepted but probably some of them may be off by a factor of 2 or more, maybe even an order of magnitude. The equations representing hypotheses, well, sometimes the hypotheses are just plain wrong. Then each of these equations has to be weighted against each other for use in the computer models, so that adds an additional variable (basically an educated guess) for each law, theory, and hypothesis. This is where the models are tweaked to mimic past climate measurements.

The SCIENTIFIC METHOD is: (1) Following years of academic study of the known physical laws and accepted theories, and after reviewing some data, come up with a hypothesis to explain the data. (2) Develop a plan to obtain and analyze new data. (3) Collect and analyze the data, this may even require new technology not previously available. (4) Determine if the hypothesis is correct, needs refinement, or is wrong. Either way, new data is available for other researchers. (5) Submit results, including data, for peer review and publication.

The output of the computer models run out nearly 90 years forward is considered to be data, but it is not a measurement of a physical phenomenon. Also, there is no way to analyze this so called data to determine if any or which of the hypotheses in the models are correct, need refinement, or are wrong. Also, this method cannot indicate if other new hypotheses need to be generated and incorporated into the models. IT JUST IS NOT THE SCIENTIFIC METHOD.

The worst flaw in the AGW argument is the treatment of GCM computer generated outputs as data. They then use it in follow on hypotheses. For example, if temperature rises by X degrees in 50 years, then Y will be effected in such-and-such a way resulting in Z. Then the next person comes along and says, well, if Z happens, the effect on W will be a catastrophe. "I need (and deserve) more money to study the effects on W." Hypotheses, stacked on hypotheses, stacked on more hypotheses, all based on computer outputs that are not data, using a process that does not lend to proof using the SCIENTIFIC METHOD.
By Nick

7/22/09 at 2:55 p.m.

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I think oil shortage is a more likely demise of Las Vegas. We need the tran and better mass transit.

Waiting until gas is too expensive will be too late
By GunslingerA10

7/22/09 at 3:42 p.m.

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I have a very similar philosophy: Garbage in -- Garbage out!
By goingbust

7/22/09 at 3:52 p.m.

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I'm sitting about 8 miles from 18,380,000,000 (18.3 billion) acre-feet of fresh water (5,438 cubic miles).

Jellus, much?
By AngryReader

7/22/09 at 4:34 p.m.

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Nuc,

Man made or not, the planet is warming up. Your 8 years of cooling is a gnat on an elephants butt compared to the hundreds of thousands of years worth of actual archealogical evidence in the Greenland ice sheets.

The northern hemisphere's polar ice cap is receding just as it has so many times in the last few million years. And it will no doubt expand again in the same repeating cycle.
No propaganda can stop that.

Now that being a given, do we really want to throw sand in the engine? Do we want to test mother nature and see how much additional Co2 we can put into the equation?

Mother Nature is a cruel and unforgiving witch. Best not to tease her.
By NucEngineer

7/22/09 at 7:08 p.m.

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AngryReader,

The head of the IPCC and the head of the WMO think that the lack of new global annual high temperatures is significant (at least it will be significant in less than 6 months).

There has been atmospheric cooling the last 8 years, and no new high global annual temperatures in the last 11 years. You may find it interesting what the head of the IPCC said 1-1/2 years ago concerning the lack of new annual high global temperatures:

http://www.reuters.com/article/idUSL1171...

Rajendra Pachauri, the head of the U.N. Panel that shared the 2007 Nobel Peace Prize with former U.S. Vice President Al Gore, said (1-1/2 years ago) that he would look into the apparent temperature plateau so far this century. "One would really have to see on the basis of some analysis what this really represents," he told Reuters 1-1/2 years ago, adding "are there natural factors compensating?" for increases in greenhouse gases from human activities.

Also in this article from 1-1/2 years ago, Amir Delju, senior scientific coordinator of the World Meteorological Organization's (WMO) climate program, said temperatures would have to be flat for several more years before a lack of new record years became significant.
Well, we are 3/4 of the way to being significant.
By Babyboomer

7/22/09 at 7:46 p.m.

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When the water runs out...That's IT !!! period, end of subject.Climate change is real,just look out your window. Weather on the East Coast,weather on the West coast and in between are seeing uncommon charges for their areas. You put the pieces together....
By skerlahdee

7/22/09 at 9:04 p.m.

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Fact: The reservoirs are 59% full.

Colorado had an above average water year, and yet the Bureau of Rec will not be able to raise the level of Powell/Mead in this water year. This indicates that current water use, without any changes, threatens the ability of the Bureau of Rec to ever contemplate a full Powell/Mead.

The article implies that climate change increases the risk of an empty Powell/Mead by a factor of ten over existing factors. This sounds like a lot, and it makes it sound like if climate change does not occur, that we will manage ok.

But on a logarithmic scale, 10x is nothing.

The news article is misleading. The real conclusion of the report is that by mid-century it is almost certain that the Colorado will fail to supply adequate water in a high percentage of the water years, with or without climate change.
By SlumpDog

7/22/09 at 11:10 p.m.

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So nobody rented Chinatown? Big disappointment.

I predict you'll be running out of air by the end of the 2010's, at least according to the headlines.

I believe the lake is being lowered until they get the contamination under control. Once the contaminants aren't leaching into Lake Mead at an unhealthy rate, they'll fill it back in with clean water.

But they are not making the most of this opportunity to put in foundations for a fun-filled water park.
By pmmart

7/23/09 at 7:08 a.m.

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Mississippi river fact

"At New Orleans, the average flow rate is 600,000 cubic feet per second.
There are 7.489 gallons of water in a cubic ft"

This equals approx. 837 acre ft.of water per minute flowing into the gulf of mexico 24 hrs a day.[Approx. one million two hundred thousand acre ft. per day]

If the southwestern states were to build a system of pipelines, canals,resevoirs and flumes to transport this totally wasted resource to the desert it would create an economic boom that would equal any past era of prosperity that our country has enjoyed since its inception.

Las vegas is entitled to 300,000 acre ft per year of water from the Colorado river per year.[ or an 8 hour daily flow of the Mississippi river]
By JR

7/23/09 at 2:33 p.m.

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NucEngineer - did you read the article you posted a link to? The first words quoted by the WMO scientist is that global warming continues. The second major comment is that last year was one of the sixth warmest years since records began in the mid 1800's.
By NucEngineer

7/23/09 at 5:08 p.m.

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JR

When you are on a roller coaster (climate) and near the top, you are there for a while. Also, recorded temperature history does not include the midevil warm period, the Roman warm period, or the Holocene maximum 6,000 years ago.

Did CO2 from power plants and SUVs cause those as well.