Skip to main content

Record rain, steep canyons fueled Colorado floods

By Matt Smith and Dave Hennen, CNN
September 20, 2013 -- Updated 2138 GMT (0538 HKT)
Railroad tracks washed from their path by floodwaters are seen in Longmont on Thursday, September 19, 2013. Massive flooding has left at least six people dead and damaged thousands of homes around the state. Railroad tracks washed from their path by floodwaters are seen in Longmont on Thursday, September 19, 2013. Massive flooding has left at least six people dead and damaged thousands of homes around the state.
HIDE CAPTION
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
Deadly floods hit Colorado
<<
<
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
>
>>
STORY HIGHLIGHTS
  • Boulder County says only 4 still unaccounted for
  • Boulder saw nearly half its annual rainfall in a single day
  • "It all happened fairly quickly," a scientist says
  • Nebraska warily watches the rising South Platte

(CNN) -- The steep, picturesque canyons that wind through Colorado's northern Front Range have been a draw for tourists, day-trippers and homebuyers for more than a century.

But when record-setting rainfall began to hit last week, those picturesque canyons became funnels that poured hundreds of tons of water per second into towns like Boulder, Longmont and Lyons and left hundreds stranded in the mountains above.

"This flood was a direct result of the large amount of rainfall that occurred in a widespread area, essentially from Denver north to almost the Wyoming state line, and for a long duration -- for about a 48-hour period last week," said Robert Kimbrough, a hydrologist with the U.S. Geological Survey in Denver.

Coloradans are still digging out from those floods, which have been up to 1,000-year events in some communities.

Colorado Flood Explainer
Colorado reels from flood devastation
Wave in Colorado 'like a tsunami'

A stream of unusually humid air that was sweeping over the area early last week helped fuel the storms. High pressure east of the mountains bumped up against a low-pressure system to the west, triggering several days of storms as moist air flowed up the peaks of the Rockies, where cold air wrung the water out of it.

The rain began September 10, with an inch recorded in Boulder. Nearly two inches fell the next day. Then on September 12, Boulder recorded 9.08 inches of rain -- nearly double the city's previous one-day record, and almost half its 20.5-inch yearly average. A forecaster in the National Weather Service office there called it "biblical."

More than 4 more inches of rain fell by the week's end, bringing the September total to more than 17 inches so far. That's boosted the yearly precipitation figure, measured from October through September, to more than 30 inches to date -- the most in 120 years of record-keeping.

The biggest rainfall amounts occurred over the foothills of the Rockies, Kimbrough said. That water poured down the mountainsides into the major tributaries of the South Platte River -- Boulder Creek and the St. Vrain, Big Thompson and Cache la Poudre rivers.

How to help

"It really originated in the streams that drain off the east side of the Continental Divide into the front range of Colorado, but it all happened fairly quickly," Kimbrough said. "Even though the leading edge was in the foothills, we did see it very quickly on the 12th in communities like Boulder and Lyons and Longmont."

Sacrifice in Colorado's historic flood
Massive flood rescue operation in Colorado

The result was six dead and about 200 who remained unaccounted for, though most of those are believed to be alive and well. Boulder County reduced its count from 109 people to four still unaccounted for on Wednesday, while in Larimer County, to the north, the number remained at 197.

Nearly 18,000 homes have been damaged statewide. Now the runoff is coursing down the South Platte into neighboring Nebraska, where forecasters are warning of flooding into the weekend.

"We're in the Grand Island area anxiously waiting to see how the Platte River responds and to see how much of the water reaches us here," Mary Harner told CNN affiliate KHAS.

Many in Colorado returned home to heartbreaking scenes. In Lyons, on the St. Vrain River 15 miles north of Boulder, high water pushed entire houses around like furniture. Streets were dotted with snapped utility poles.

Stories of grief, generosity and gratitude

The extensive damage may present long-term problems for communities even as workers scramble to make repairs, Larimer County Sheriff Justin Smith said Tuesday. Questions of how to provide emergency services to areas where roads have been washed out or protect properties where the owners have been evacuated are still being worked out, he said.

"We have a new normal in Larimer County for months, if not a few years," Smith said.

CNN's Kyung Lah, Faith Karimi and Sean Morris contributed to this report.

ADVERTISEMENT
Part of complete coverage on
This looks like a ghost ship, but it's actually the site of a tense international standoff between the Philippines and China.
July 26, 2014 -- Updated 1555 GMT (2355 HKT)
The reported firing of artillery from Russian territory is a sign Vladimir Putin has escalated the Ukraine battle, says CNN's military analyst Rick Francona.
July 27, 2014 -- Updated 0846 GMT (1646 HKT)
The young boy stops, stares, throws ammunition casings at the reporter's feet without a word.
July 27, 2014 -- Updated 1237 GMT (2037 HKT)
A picture taken on June 28, 2014 shows a member of Doctors Without Borders (MSF) putting on protective gear at the isolation ward of the Donka Hospital in Conakry, where people infected with the Ebola virus are being treated. The World Health Organization has warned that Ebola could spread beyond hard-hit Guinea, Liberia and Sierra Leone to neighbouring nations, but insisted that travel bans were not the answer.
The worst ebola outbreak in history spreads out of control in West Africa. CNN's Michael Holmes reports.
July 26, 2014 -- Updated 0048 GMT (0848 HKT)
Sure, Fido is a brown Lab. But inside, he may also be a little green.
July 24, 2014 -- Updated 2006 GMT (0406 HKT)
ITN's Dan Rivers reports from the hospital where those injured by an attack in Gaza were being treated.
July 28, 2014 -- Updated 1303 GMT (2103 HKT)
Photograph of an undisclosed location by Patrycja Makowska
Patrycja Makowska likes to give enigmatic names to the extraordinarily beautiful photographs she shoots of crumbling palaces.
July 23, 2014 -- Updated 0804 GMT (1604 HKT)
When the Costa Concordia and its salvage convoy finally depart Giglio, the residents will breathe a sigh of relief -- and shed a tear.
July 25, 2014 -- Updated 1808 GMT (0208 HKT)
Flight attendants are wearing black ribbons to show solidarity with fallen colleagues in "a tribute to those who never made it home."
CNN joins the fight to end modern-day slavery by shining a spotlight on its horrors and highlighting success stories.
Browse through images from CNN teams around the world that you don't always see on news reports.
ADVERTISEMENT