National Geographic Daily News
A home and car are stranded after a flash flood in Coal Creek destroyed a bridge near Golden, Colorado.

A home and car are stranded after a flash flood in Coal Creek destroyed the bridge near Golden, Colorado, September 12, 2013. Scientists say drought, fires, and global warming may have helped spur the flood.

Photograph by Rick Wilking, Reuters

Brian Clark Howard

National Geographic

Published September 14, 2013

This story is part of a special National Geographic News series on global water issues.

University of Colorado, Boulder law school professor Brad Udall has long written and lectured about water issues in the American West, but this week’s Colorado floods have brought the subject to his doorstep.

Four people have lost their lives in flooding this week that has engulfed swaths of Colorado and that has forced thousands to evacuate their homes.

Udall, director of the University of Colorado, Boulder’s Getches-Wilkinson Center for Natural Resources, Energy and the Environment says that the Boulder area (see map) has received more rain in the past three days (up to 15 inches, or 38 centimeters) than the previous precipitation record for a whole month.

Udall’s house sits about 30 feet (9 meters) from a creek that is normally dry this time of year. In the past two days, he said the creek rose more than five feet (1.5 meters), and has become a raging stream that’s 20 feet (6 meters) wide.

“[Thursday] night I had a hard time going to sleep because of the ominous rumblings of large boulders tumbling down the creek bed,” Udall said. His house narrowly escaped major damage, but many neighbors weren’t so lucky.

U.S. President Barack Obama declared an emergency for Boulder, Larimer, and El Paso Counties on Friday and the Federal Emergency Management Agency (FEMA) has deployed four rescue teams to the area, the most ever in the state.

Just as troubling as all the damage, Udall says, is that this week’s floods do not fit into the usual pattern of high water in the West.

The floods were not the result of springtime rains or intense summer thunderstorms that quickly dump large amounts of rain in concentrated areas, such as the 1976 Big Thompson or 1997 Fort Collins floods.

“This was a totally new type of event: an early fall widespread event during one of the driest months of the year,” Udall said.

So what explains the anomaly?

Sandra Postel, National Geographic’s Freshwater Fellow, said that the long-term drought that has parched the area and gripped much of the Colorado River Basin over the past 14 years may be partly to blame for the severity of the floods.

Drought tends to harden the soil, she said. When rains do come, less of the water can absorb into the ground, so it quickly runs off the land.

Similarly, fires can lead to worse flooding, because they remove vegetation that can slow down and trap rainfall, Postel said. (See “Fire and Rain: The One-Two Punch of Flooding After Blazes.”) In 2012, the Boulder area was afflicted by the Flagstaff Fire. In 2010, the Fourmile Canyon fire caused damage to Boulder County worth $217 million.

Scientists have warned that increasing frequency and severity of wildfires and droughts may be symptoms of climate change, as much of the planet warms. That, in turn, can lead to more floods.

In June, President Obama told an audience at Georgetown University, “Droughts and fires and floods, they go back to ancient times. But we also know that in a world that’s warmer than it used to be, all weather events are affected by a warming planet.”

Udall said that while current science can’t pin any particular extreme weather event to climate change, this week’s flooding is likely a reflection of global warming, at least in part.

The connection, he said, “might be 10 percent or it might be 90 percent, but it isn't zero percent and it isn’t 100 percent.”

Udall added that warmer air means more moisture can be held by clouds, which can lead to more rain:“As the climate warms further, the hydrologic cycle is going to get more intense.”

“Between the fires last year and this year, the unprecedented and continuing drought in the Colorado River, and now this shocking event,” he continued, “climate change feels very real to me.”

Follow Brian Clark Howard on Twitter and Google+.

38 comments
Romeo Caoili
Romeo Caoili

Global climate change is real, it is done slowly, then SURPRISED,.!!!

Hannah Trilling
Hannah Trilling

If we kill everyone then we wouldn't have cars or factories or...... Hence no more pollution or other problems.

Kevin Doan
Kevin Doan

we could be prevent it , unless we dont use cars, no factory,....so on.....

Adri A
Adri A

This is crazy to think that climate change can be the cause of all these other disasters. Me, being in Environmental Science have become very interested in these types of topics. This is just a question...what are some effective ways we can prevent climate change??

Javier Salvador
Javier Salvador

Everybody must to see "Chasing Ice". A film to James Balong. That's amazing.The global warming is an a fact

Emma Halls
Emma Halls

we need to wake up and realize what global warming is doing to the planet

Jack Swanzy
Jack Swanzy

It might be 10%?  Might be 9%, 5%?  Just guessing, my bias, etc.  Mouth shut isn't an option for the ignorant.  Focus on the loss of life, the recovery, leave the conjecture for now.

Dave Maney
Dave Maney

Kind of hate to break this to Sandra the "Freshwater Fellow" (who was pitching her unsupported "this is global warming" line to Canadian radio yesterday while I was driving across Ontario), but this storm was caused by a stalled cold front. Back to the drawing board, Sandy. http://www.denverpost.com/weathernews/ci_24081189/flood-expert-boulder-experiencing-100-year-flood?source=rss&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+dp-weather+%28Denver+Post%3A+News%3A+Weather%29

Tom Christoffel
Tom Christoffel

Emergency preparedness thinking has advanced since 9/11 and Katrina. Were not Boulder City, County, other Denver area jurisdictions and the State of Colorado working ceaselessly for decades, the losses would have been greater. Shifting planning to 500 year flood plains will increase the resilience of our communities, but people will complain - they like to build on the water. The Dutch, masters of water management were shocked by the Katrina events and went there to study and assist in planning. Where the old engineering idea was to manage the water with dams and levees, the new idea is "make room for the river." The fact that there's a tiny creek in a large canyon does not account for the massive water that historically cut the canyon. Expect that river to come to life again; and prepare for it. Even if that is 500 years away. Humans have very short memories - an easily dismiss history, as well as current anomalies which foreshadow great waves of change .  

John C.
John C.

Nature | Editorial

Extreme weather

Better models are needed before exceptional events can be reliably linked to global warming.

19 September 2012

“To make this emerging science of ‘climate attribution’ fit to inform legal and societal decisions will require enormous research effort.

At a workshop last week in Oxford, UK, convened by the Attribution of Climate-related Events group — a loose coalition of scientists from both sides of the Atlantic — some speakers questioned whether event attribution was possible at all. It currently rests on a comparison of the probability of an observed weather event in the real world with that of the ‘same’ event in a hypothetical world without global warming. One critic argued that, given the insufficient observational data and the coarse and mathematically far-from-perfect climate models used to generate attribution claims, they are unjustifiably speculative, basically unverifiable and better not made at all. And even if event attribution were reliable, another speaker added, the notion that it is useful for any section of society is unproven."

http://www.nature.com/news/extreme-weather-1.11428

ReX Henri
ReX Henri

With an estimated ~ 4.4billion people on "space ship" earth.  When in earths recent  history, of 4.6 billion years, has the population been at this level?   I submit that the global warm up is accelerating with this many residents and undoubtedly  having a direct impact on the earth.  Denial over this and other facts is just not a wise conclusion and frankly not an option.    I know I am preaching to a big choir group.

Mark Berger
Mark Berger

The world is changing due mankind's irresponsible use of the Earth, but we don't want to admit it:

"Humanity’s overuse and abuse of the world is now changing the natural balance, and this change is not in your favor. And even at this moment, nations and peoples do not seem to comprehend the magnitude of what is happening. People do not want to give up their privileges. Networks of trade and the exploitation of resources are now well established. People do not want to restrain themselves." - from the revelation "Nature and Natural Disasters" in the New Message from God

Raymond Cunningham
Raymond Cunningham

 The precipitation records for the area suggest that early September is part of the area's wet season.  The USGS report on the 1976 Big Thompson flood says: "Although rainstorms and flash floods the magnitude of the Big Thompson flood are infrequent in any one location, they are common from May to October in much of Colorado."

And when did the first week of September get moved from summer to early fall?  

Evan Ravitz
Evan Ravitz

PS: Most of Northern Mexico has been in a megadrought which started almost 25 yrs ago and wiped out much of the cattle business more than once. A consortium of Mexican universities and govt agencies concluded a couple of yrs ago that Northern Mexico was affected by climate change more than anywhere but the poles.

Evan Ravitz
Evan Ravitz

I spend 2+ months in the wilderness each year, including guiding backpackers in Mexico's Copper Cyn. Both there and in the high country near Aspen I frequent, almost ALL the erosion I've seen in the last 30 years has been in the last 5 years. In 2010 part of Copper Cyn had a 500-yr flood that wiped out 60 mature orange trees and all the soil under them, and moved 15' boulders. Here's a photo showing the remnant of the orange grove: https://picasaweb.google.com/115298787940212532225/CopperCanyon2011#5596609724210120018

Michael Cohen
Michael Cohen

Another problem is using Silver Iodine is that it is toxic and  will cause severe health problems for the survivors.

Michael Cohen
Michael Cohen

These floods are man made. See Colorado cloud seeding on google.  For weeks SILVER IODINE GENERATORS have been blasting the clouds over the Rockies in order to increase rainfall, but the project backfired causing these massive floods. In 1952 the British government had planes spraying silver iodine over a town and caused massive flooding killing hundreds They kept it secret until now and you can see similar destruction found Colorado. see Cloud seeding on google

Although this information can be found on line, the major media outlets are refusing to report these facts.. The state is totally responsible for all damages so they want to keep this info from the public.

Paul M.
Paul M.

Stop the climate blame fear mongering!

Prove to us deniers and former believers that science has a consensus that it WILL be an inevitable crisis not just a worthless consensus that it might possibly be a crisis. If a "maybe" consensus is good enough for you to condemn your own kids, YOU are the bible thumper and the fear mongering neocon. 
All science has to do to end denial is agree it WILL be not just might be a crisis.

Cheryl Wisecup
Cheryl Wisecup

My heart goes out to all of the families affected by the massive flooding in Colorado.  I hope the government decides to provide accurate information this time regarding how to handle the water damage and mold.  There is a lot of misinformation about the proper procedures to use and a lot of misinformation about the health effects.  For accurate information about the health effects of mold, check out the Global Indoor Health Network.  Be sure to read GIHN's position statement that discusses the diagnosis and treatment of illness caused by mold. 

Rick Fitzgerald
Rick Fitzgerald

@Michael Cohen According to Live Science, cloud seeding could not have made the amount of rain fall. Nothing they have could produce 15 inches of rain. Colorado's terrain is almost like the desert where 3 inches totally wipes out vegetation. They have had a drought for years and they don't call it the "Rocky Mountains" for nothing. We had to adjust in the desert for the "100 year flood" to happen twice in one year but no one builds in arroyos where most of the damage is done. Some say they are colder now and some say they are warmer now. We simply trade weather it seems every 30 years or so. Our earth stopped warming in 1998 and has remain relatively stable.

James Wine
James Wine

@Paul M. Paul, you don't understand the way the scientific community works.  We almost always use the subjunctive rather than the certain statement.

  Is the sun going to rise tomorrow?  It is extremely likely.  the probability distribution that seems to fit that phenomenon indicates that there is a very small probability that it won't.   Comprende? 

Tom Mengel
Tom Mengel

@Paul M. More to the point: learn what Science actually is and how the scientific method works.  If you want St. Albert Einstein of the silver hair dancing down from the sky on magic light-beams saying climate change is absolutely for real forget it.  Science is not the Bible and as my old Physics Professor once said "in science there are no absolutes".  And what make science so powerful is that geneticists >>never<< fully agree so the body of knowledge can always change.

c kaf
c kaf

@Sisi van Dijk @Paul M. No kidding. Why write something that does make any sense.

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