Unprecedented Cut in Colorado River Flow Ordered, Due to Drought

By: Dr. Jeff Masters , 3:20 PM GMT on August 20, 2013

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For the first time in history, the U.S. government has ordered that flow of Colorado River water from the 50-year-old Glen Canyon Dam be slashed, due to a water crisis brought about by the region's historic 14-year drought. On Friday, the Federal Bureau of Reclamation--a division of the Department of Interior that manages water and electric power in the West--announced that it would cut water released from Lake Powell's Glen Canyon Dam by 750,000 acre-feet in 2014. An acre-foot is the amount of water that will cover an acre of land one foot deep; 750,000 acre-feet is enough water to supply at least 750,000 homes for one year. The flow reduction will leave the Colorado River 9% below the 8.23 million acre feet that is supposed to be supplied downstream to Lake Mead for use in California, Nevada, Arizona and Mexico under the Colorado River Compact of 1922 and later agreements. "This is the worst 14-year drought period in the last hundred years," said Upper Colorado Regional Director Larry Walkoviak in a Bureau of Reclamation press release.

In the winter of 2005, Lake Powell reached its lowest level since filling, an elevation 150' below full pool. Lake levels recovered some in during 2005 - 2011, but the resurgence of severe to extreme drought conditions have provoked a steep decline in 2012 and 2013, with the lake falling 35' over the past year. As of August 18, 2013, Lake Powell was 109' below full pool (45% of capacity), and was falling at a rate of one foot every six days.


Figure 1. Satellite comparisons of water levels in Arizona and Utah's Lake Powell between 1999 and 2013 show a huge reduction in the amount of water in the lake. Image credit: NASA Earth Observatory.


Figure 2. From October 1, 2012 - July 31, 2013, precipitation over the Colorado River Watershed was about 80% of average. Image credit: Colorado Basin River Forecast Center.

Las Vegas' Water Supply, Lake Mead, Near a Record Low
Downstream of Lake Powell lies Lake Mead, filled in 1936 when Hoover Dam was completed. Lake Mead supplies Las Vegas with ninety percent of its drinking water, and the water level of Lake Mead is expected to fall by eight feet in 2014 due to the lower water flow levels out of Lake Powell ordered on Friday. Lake Mead has fallen by 100 feet since the current 14-year drought began in 2000, and the higher of the two intake pipes used to supply Las Vegas with water from the lake is in danger of running dry. As a result, a seven-year, $800 million project is underway by the Southern Nevada Water Authority to build a third intake pipe that will tap the deepest part of the reservoir. This so-called "third straw" is scheduled to be available late in 2014, which may be cutting it close, if the Colorado River watershed experiences another year of drought as severe as in 2012 - 2013. Southern Nevada has done well to reduce water usage, though--the region's annual water consumption decreased by nearly 29 billion gallons between 2002 and 2012, despite a population increase of more than 400,000 during that span.


Figure 3. Lake Mead water levels from 1938 - 2013 in July show a precipitous drop since drought conditions gripped the Western U.S. in 2000. The Lake Mead photo was taken by wunderphotographer LAjoneson June 29, 2007, when the lake had a "bathtub ring" 109' tall. Water level data from The Bureau of Reclamation.


Figure 4. Workers handle the main drive sections of the tunnel boring machine that is drilling a 3-mile long tunnel through solid rock to supply Las Vegas with water from Lake Mead. The new intake tunnel is designed to maintain the ability to draw upon Colorado River water at lake elevations as low as 1,000 feet above sea level. The lake already has two intake pipes, and the higher of these will go dry when the lake level hits 1050' - 1075'. As of August 2013, the Lake Mead water level was 1106' above sea level, which is 114' below full pool, but 24' above the record low water level of 1081' set in November 2010. Image credit: Southern Nevada Water Authority.

Drought conditions worsen over Southwest U.S. in August
According to the U.S. Drought Monitor, the Western U.S. drought peaked in July 2002, when 79% of the West was in at least severe drought, and 45% of the region was in the two highest categories of drought--extreme to exceptional. However, drought conditions have been steadily intensifying this summer. The August 13, 2013 Drought Monitor report showed that drought conditions in the Western U.S. are now the worst since 2004, with 78% of the West in at least severe drought, and 20% in the two highest categories of drought, extreme and exceptional. The latest U.S. Seasonal Drought Outlook, issued on August 15, calls for drought to remain entrenched over the large majority of the Western U.S. through the end of November.


Figure 5. As of August 13, 2013, severe to exceptional drought gripped nearly all of the Colorado RIver's watershed in Arizona, Utah, New Mexico, Wyoming, California, and Colorado. Image credit: NOAA/NESDIS/NCDC.

Causes of the great Western U.S. drought
It is well-known that natural variations in sea surface temperature patterns, such as seen from the El Niño/La Niña oscillation, can influence storm tracks and can cause prolonged periods of drought. These natural variations likely had a hand in causing the great 2000 - 2013 Western U.S. drought. However, changes in the amount of sea ice covering the Arctic can also have a major impact on Northern Hemisphere atmospheric circulation patterns. We must consider if global warming, which has led to a 50% decline in summer Arctic sea ice extent since 1979, may be altering storm tracks and contributing to drought. In 2004, Lisa Sloan, professor of Earth sciences at UC Santa Cruz, and her graduate student Jacob Sewall published an article in Geophysical Research Letters, Disappearing Arctic sea ice reduces available water in the American west. An accompanying news release explained that their climate models found "a significant reduction in rain and snowfall in the American West” as a result of Arctic sea ice loss:

What they found was a change in atmospheric circulation patterns that caused a small northward shift in the paths of winter storms over western North America. This shift in winter storm tracks resulted in significantly reduced winter precipitation from southern British Columbia to the Gulf of California. In some areas, average annual precipitation dropped by as much as 30 percent. The reductions were greatest along the West Coast, with lesser changes further inland. But even as far inland as the Rocky Mountains, winter precipitation fell by 17 percent.

The sea ice acts like a lid over the ocean surface during the winter, blocking the transfer of heat from the ocean to the atmosphere, Sewall explained. Where the sea ice is reduced, heat transfer from the ocean warms the atmosphere, resulting in a rising column of relatively warm air. The shift in storm tracks over North America was linked to the formation of these columns of warmer air over areas of reduced sea ice in the Greenland Sea and a few other locations.


A follow-up paper by Dr. Sewall in 2005, "Precipitation Shifts over Western North America as a Result of Declining Arctic Sea Ice Cover: The Coupled System Response", used a more sophisticated modeling technique but confirmed the results of the 2004 paper. In a June 2013 interview with climateprogress.org, Dr. Sewall commented:

"I think the hypothesis from 2004 and 2005 is being borne out by current changes. The only real difference is that reality is moving faster than we thought/hoped it would almost a decade ago."


Figure 6. The area of the Western U.S. in drought peaked during 2002 - 2004, but during 2013 has been approaching levels not seen since 2004. Image credit: U.S. Drought Portal.

Western North America drought of 2000 - 2004 the worst in over 800 years
The Colorado River's water woes are due to an extraordinary 14-year drought that began in 2000, which peaked during 2000 - 2004. A 2012 study titled, Reduction in carbon uptake during turn of the century drought in western North America, found that the 2000 - 2004 drought was the most severe Western North America event of its kind since the last mega drought over 800 years ago, during the years 1146 - 1151. The paper analyzed the latest generation of climate models used for the 2013 IPCC report, which project that the weather conditions that spawned the 2000 - 2004 drought will be the new normal in the Western U.S. by 2030, and will be considered extremely wet by the year 2100. If these dire predictions of a coming "megadrought" are anywhere close to correct, it will be extremely challenging for the Southwest U.S. to support a growing population in the coming decades.


Figure 7. Normalized precipitation over Western North America (five-year mean) from 22 climate models used to formulate the 2013 IPCC report, as summarized by Schwalm et al., 2012, Reduction in carbon uptake during turn of the century drought in western North America. The horizontal line marks the precipitation level of the 2000 - 2004 drought, the worst of the past 800 years. Droughts of this intensity are predicted to be the new normal by 2030, and will be considered an outlier of extreme wetness by 2100. The paper states: "This impending drydown of western North America is consistent with present trends in snowpack decline as well as expected in-creases in aridity and extreme climate events,including drought, and is driven by anthropogenically forced increases in temperature with coincident increases in evapotranspiration and decreases in soil moisture. Although regional precipitation patterns are difficult to forecast, climate models tend to underestimate the extent and severity of drought relative to available observations. As such, actual reductions in precipitation may be greater than shown. Forecasted precipitation patterns are consistent with a probable twenty-first century megadrought." Image credit: Schwalm et al., 2012, Reduction in carbon uptake during turn of the century drought in western North America, Nature Geoscience 5, 551-555, Published online 29 JULY 2012, DOI: 10.1038/NGEO1529, www.nature.com/naturegeoscience.

Related posts
Lessons from 2012: Droughts, not Hurricanes, are the Greater Danger, my November 2012 post.

National Geographic has an excellent interactive satellite image that shows the difference in Lake Powell water levels between 1999 and 2013.

How Two Reservoirs Have Become Billboards For What Climate Change Is Doing To The American West, August 12, 2013 climateprogress.org post by Tom Kenworthy.

Scientists Predicted A Decade Ago Arctic Ice Loss Would Worsen Western Droughts. Is That Happening Already?, June 2013 post by Joe Romm at climateprogress.org.

Twenty Cities At Risk of Water Shortages, August 14, 2013 wunderground news post by Nick Wiltgen

References
Sewall, Jacob O., 2005, Precipitation Shifts over Western North America as a Result of Declining Arctic Sea Ice Cover: The Coupled System Response, Earth Interact., 9, 1–23. doi: http://dx.doi.org/10.1175/EI171.1

Sewall, J.O., and L.C. Sloan, 2004, Disappearing Arctic sea ice reduces available water in the American west, Geophys. Res. Lett., 31, L06209, doi:10.1029/2003GL019133. Accompanying news release.

Jeff Masters

Lake Mead - low water (clicks4fun)
Colorado River has been struggling to survive. Predictions of its future are grim in the headlines. Hopefully scientists will figure out how to resolve this bad situation.
Lake Mead - low water
Storm Clouds over Lake Powell, Glen Canyon NRA (catjuice)
Lake Powell, Glen Canyon National Recreation Area, AZ
Storm Clouds over Lake Powell, Glen Canyon NRA

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110. 7544
thanks for models looks like lights camera action in 4 days onward to sept what will the show bring .
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Nevermind, Fernand just decides to weaken and the remnants actually goes over the northern Leewards, however Gabrielle gathering strength.

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Quoting Cat5hit:


Prostitution is/was legal in the area too....

Actually, it's illegal in two of Nevada's counties with the largest populations, Clark (Las Vegas)county and Washoe (Reno), It's also illegal in Lincoln because of legal snit between one owner and the county commission.
Member Since: October 2, 2004 Posts: 0 Comments: 12754
Possible we may get our first hurricane before August ends.
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Thank you Dr. Masters! Good Morning Class!
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There's a Weakness opening up ahead of Fernand.


Fernand weakening... The wave behind him getting stronger.
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Since its quiet in the Atlantic for now, I posted a blog about what inspired me to love weather if anyone is interested.

Link
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240 hrs. the ridge is rebuilding in, but I think our first system is already too far north to be an impact to any land areas the one behind it though will need to be watched.

img src="">
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102. rod84
could of,should of would of
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Quoting 93. 69Viking:


That combined with gambling is what made Vegas.
With all the diseases that exist today, prostitution is a gamble in and of itself. lol
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Quoting 54. SouthernIllinois:
Dog Days of summer is the name of the game here...



Ahh, what I would give to see a low of 65!
Member Since: August 25, 2006 Posts: 1 Comments: 3010
Good morning

The Caribbean is looking more interesting as the low/trough I have been following for a while is starting to ramp up the convection below Hispaniola. The 850 vort is progressing basicall due west after lifting to the Central portion of the basin last night and the "spin" with the feature can be seen at 15N and 69W if you view this loop after clicking on the image to increase the zoom. Shear is relatively high in that area at the moment but decreases to the immediate West.

High pressure is to the South of the area and if it expands to the N could become a catalyst for development once the system passes 75 W IMO.

The other low East of the islands continues to drift off to the West as well. Both areas are worth monitoring.
Member Since: August 19, 2006 Posts: 0 Comments: 15687
Quoting 87. CybrTeddy:


Personally, I love long-tracked and long lived Cape Verde hurricanes, and they're pretty fun to watch when they go out to sea. We haven't seen one in quite a bit of time.

Hurricane Igor and Julia 2010.
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Published on May 29, 2013

Scheduled for completion in 2014, Intake No. 3 will supply drinking water to the residents and businesses of the Las Vegas Valley. Watch as workers use a tunnel boring machine to carve a three-mile tunnel

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Quoting 43. Cat5hit:


Prostitution is/was legal in the area too....


That combined with gambling is what made Vegas.
Member Since: August 25, 2006 Posts: 1 Comments: 3010
High across America and High in the east Atlantic likely means troughing in between this one should recurve OTS.

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Quoting 80. ILwthrfan:




Some areas are warming others are cooling, yep, very neutral. We cant even say its closer to La Niña or its closer to El Niño, its neither.
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Such a strong trough with such early development favors recurvature at this time, not guaranteed however.
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Another strong wave emerging off of Africa behind "Fernand".
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do you see how big that high is in the northeast and the mid-west!! my god!!
Member Since: March 12, 2013 Posts: 8 Comments: 12829
Quoting 78. scottsvb:
If the system coming off Africa in a few days gets too strong too early, it will move NW on days 5-7 and be a fish storm east of 60W


Personally, I love long-tracked and long lived Cape Verde hurricanes, and they're pretty fun to watch when they go out to sea. We haven't seen one in quite a bit of time.
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Quoting 21. Patrap:
Don't worry about it.

Itsa cycle..

It's happened before..

God will fix it

Is it really that Bad?

Why dont we build a pipeline?

It's not Climate Change.

Al Gore.

Its a Liberal plot.

..yada,yada, yada....



It really is not much different than when one is warned by a doctor to end their smoking and drinking and/or bad diet before its too late.


Even though the signs are already there of failing health, people often respond with "these darn things ain't killed me yet"

Sadly, people often don't want to be bothered with what's at stake because it requires a significant change in life. We are all that way in some aspect of life.
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It will be impossible to pay off this debt. It's in the trillions. And no politicians (both parties) will have the guts to even try.
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The GFS beginning to pick up on a Strong Tropical Wave emerging from Africa on Friday and becoming Fernand.


The pattern favors Westward movement until it reaches the islands, could be an interesting system to track if it manages to develop and stay alive.
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Quoting 51. RitaEvac:
At the rate America is going....Government debt, individual debt, cost of living ever increasing, population ever increasing, building in desolate areas where water is scarce, building along the coasts in masses prone to storms, and the entertainment industry as a number 1 priority......I expect America to fall like Rome in less than 100 years guaranteed.


Not that your point isn't well taken but government debt is on the decline. Just sayin
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The population in the US and many European countries, such as Italy, is actually falling to the degree that the population is not even staying constant. This is the reason behind many government policies. The heat is back on in NOLA today!!!!
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Quoting 57. JLPR2:
Hmm...



Still neutral, but interesting.


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Quoting 51. RitaEvac:
At the rate America is going....Government debt, individual debt, cost of living ever increasing, population ever increasing, building in desolate areas where water is scarce, building along the coasts in masses prone to storms, and the entertainment industry as a number 1 priority......I expect America to fall like Rome in less than 100 years guaranteed.


I, too, see many parallels with the events leading to the fall of the Roman Empire in 410CE with what is happening in our current time. Probably not taught in history classes in school anymore. All the major metropolitan areas are in trouble and can't exist without our current logistics network. It's not going to be pretty.
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If the system coming off Africa in a few days gets too strong too early, it will move NW on days 5-7 and be a fish storm east of 60W
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Quoting 67. Drakoen:
It appears we could see some true Cape Verde development off the African coast with a wave poised to emerge this Friday.


Hi Drak. May be our next development but it will depend on if the dry air thins out.
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Quoting 73. JLPR2:


It's looking good and all the convection that emerged recently with that low pressure around 20N should give it a nice moist area to work with.



Though the one behind it looks more promising.


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Perhaps good ventilation for fanning of the clouds to the north and south.

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Quoting 67. Drakoen:
It appears we could see some true Cape Verde development off the African coast with a wave poised to emerge this Friday.


It's looking good and all the convection that emerged recently with that low pressure around 20N should give it a nice moist area to work with.



Though the one behind it looks more promising.
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The wave appears to be located near 4W over Africa and is marked by an 850mb vorticity maximum on the equatorward end of the wave axis.
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I hope everyone getting the popcorn ready to watch the tropical storm in four days from now.
Member Since: March 12, 2013 Posts: 8 Comments: 12829
With the front that far south into N Florida...expect the ridge to slide to PR..keep a eye on the SW carribean for something wanting to come NNW early next week. Just something to watch out for.
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Nice simulated satellite view here, not only shows our potential storm in the Atlantic, but the frontal boundary from northern FL. all the way to south of Iceland.



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Member Since: March 12, 2013 Posts: 8 Comments: 12829
It appears we could see some true Cape Verde development off the African coast with a wave poised to emerge this Friday.
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Quoting 62. GTstormChaserCaleb:
Stronger on this run, down to 996 mb.



Set up looks good on the GFS....strong high to the north means lower pressures to the south to give this a good shot of developing in 3 days. I don't think it will be a 999mb in 4 days or 996 in 5 but 1002-1004 TS in 4 days sounds about right.
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You never know, we might get a good storm this week after all. Not consistent yet on the GFS, but something to watch.
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Switching gears for a significant water story in the Western Pacific.

Fukushima Springs Another Leak in Battle With Radiated Water
By Jacob Adelman & Yuji Okada - Aug 20, 2013 3:21 AM CT


Tokyo Electric Power Co. (9501) reported another breach of the defenses it has built at the Fukushima nuclear plant in its more than two-year struggle to stop leaks of radioactive water into the soil and sea.
Just weeks after the utility backtracked from earlier statements and acknowledged radiated water was flowing into the Pacific Ocean at a rate of 300 tons a day, it has found another leak from a storage tank.
Prime Minster Shinzo Abe weighed in on the disaster response this month, signaling that Tokyo Electric alone isn’t up to the task. The government has yet to say what other measures it’s considering to contain the worst nuclear disaster since Chernobyl, including bringing in foreign expertise.
“Two years down the line from the accident, I would expect there would have been better plans,” said Tom O’Sullivan, an analyst with Tokyo-based energy consultant Mathyos. “It’s a huge logistical challenge and perhaps the Japanese government should have gotten involved at an earlier stage.”
Shinichi Tanaka, the chairman of Japan’s Nuclear Regulation Authority, has said the water leaks are getting out of control and creating a state of emergency, according to Shinji Kinjo, who leads a disaster task force for the regulator.

....more
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Quoting 47. AllBoardedUp:
It stopped raining here in the Galveston area! Boo! That didn't last long.

I appears thought as its going to be off and on the rest of the day.


I think the coast is supposed to have more moisture stream in throughout the week and eventually make it inland as well as the week progresses. I hope y'all get some nice showers from it.
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Stronger on this run, down to 996 mb.

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Quoting 46. JeffMasters:



in three days from now!!
Member Since: March 12, 2013 Posts: 8 Comments: 12829
I dont see anything freaking out now that the GFS is showing development in 3-4 days. LOL!



Second run that shows this low, so far it is stronger on this one.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.