March 20, 2013 News » Cover Story

Why flooding off the Waldo Canyon burn scar will be fierce 

Black water

They knew even when the flames were still licking the mountaintops.

And ever since those smoky July days, they have been issuing warnings, conducting studies, digging pools into the burned dirt, dropping mulch from helicopters, and laying felled logs along the bare hillside. But even with all the preparation, much is left to fate.

The summer monsoon season approaches, and 18,247 acres of blackened earth waits, ready to unleash a fury that could prove more damaging than the fire that killed two people and destroyed nearly 350 homes. Experts agree: One fast, hard rainstorm over the Waldo Canyon burn scar could send a torrent downhill, taking houses, businesses, roads, utility lines and lives.

It could come in the afternoon, rushing toward crowds of tourists in downtown Manitou Springs. It could come in the middle of the night, catching Pleasant Valley neighborhood residents as they sleep.

Some who watched the Waldo Canyon Fire approach through their windows may feel they know the drill: Pack your bags and wait for the knock on the door. But most will receive no such direct warning in a flood evacuation. In fact, those who have studied our risk say they are struggling to relay a single, essential message: You're on your own this time around, and you'd better be ready.

Carol Ekarius, executive director of the Coalition for the Upper South Platte, has directed fire and flood recovery work for the 2002 Hayman Fire and other large burns. She's seen her share of devastating floods. Still, in terms of flood risk, she calls Waldo "the scariest fire in the country."

"Have you got your ark ready?" she asks, with a nervous chuckle.

Another expert puts it even more bluntly. David Zelenok is an engineer who retired from the city of Colorado Springs in 2005 after nearly 15 years overseeing the city's public works, stormwater and transportation infrastructure. Concerned about flood risks in his old hometown, he began crunching raw numbers. The results were disturbing: A big storm within the next 10 years is a virtual mathematical certainty, and unless significant mitigation work is done, he predicts that storm could bring a billion or more gallons of water into the Springs over several hours. That's about the contents of Crystal Creek Reservoir.

"The kinds of fatalities I think we'll see — and I pray I'm wrong — is in the dozens, or perhaps even hundreds," he says.

The first warning

Last July 30, just weeks after the fire was fully contained, Colorado Springs got a rainstorm.

Tom Magnuson, the local warning coordination meteorologist with the National Oceanic and Atmospheric Administration, says it dumped about 1.5 inches of rain on 80 percent of the burn scar over about three hours. A smaller portion of the burn, in the West Monument Creek drainage, saw nearly 2 inches in an hour and half.

The results were dramatic. Mud slides closed U.S. Highway 24 near Cascade, with the Colorado Department of Transportation reporting sludge five feet deep in places. As the mud coursed down the hill, it damaged the playground at Ute Pass Elementary School.

Downstream at Rainbow Falls, where Fountain Creek runs under U.S. 24 before heading into Manitou Springs, the water carved out a new landscape. Monument Creek, near the Air Force Academy, reached 97 percent capacity and Fountain Creek, near downtown, reached 98 percent.

Worst of all, stormwater put a low-lying water treatment plant near the Air Force Academy at risk of damage, and busted the Pine Valley Pipeline. That pipeline can carry 80 percent of Colorado Springs' water into town from Rampart Reservoir if and when the main line, the Stanley Canyon Tunnel, breaks down or needs maintenance.

Crews are still scrambling to fix that bust. In the meantime, if anything goes wrong with Stanley Canyon, the Springs will have a massive water shortage. In fact, some northern portions of the city and the Air Force Academy may not have fresh water service at all, says Mark Shea, Utilities' watershed planning supervisor.

In sum, the July storm was a doozy in terms of damage. But in terms of rainfall rate, it really wasn't that big. Magnuson says the burn scar will likely see a storm like this one, every year.

"That was not a worst-case scenario by any stretch," he says.

The worst-case scenario is this: Inches of rain falling hard and fast within an hour over the entire burn scar. If the ground is already wet from earlier rain, it will be worse. If the storm happens this year, it will be more severe than if it happens four years from now, when vegetation has had a chance to take root, and local governments and agencies have had more time to build structures that can slow down water and hold back debris.

Magnuson notes that last summer, a storm dumped three to four inches of rain in a couple hours on the Briargate area. A September storm dumped around 1.25 to 1.67 inches of water on the burn scar, but the water came slowly over a period of hours, giving the ground time to absorb it.

Under slightly different conditions, either of those storms would have caused havoc. In fact, the U.S. Forest Service has studied the effects of just 1.75 inches of rain in an hour on the burn scar, which is considered a 10-year flood. They'd be catastrophic.

The power of water

Green Mountain Falls Mayor Lorrie Worthey sits still, staring at the map, a tear gliding its way down her cheek.

Her town was long known for its waterfalls, a pretty gazebo and not much else. But in 2012, it made headlines. Last summer, of course, it came close to burning in the Waldo Canyon Fire. And earlier in the year, arsonists burned down its historic town hall, and with it, some of the town's treasured historical documents.

Now, Worthey and the rest of Green Mountain Falls' trustees must gather here, in the back room of the Joyland Falls Church Center, to conduct the town's business. On Feb. 19, that business is grim.

El Paso County Commissioner Sallie Clark, Ekarius and Patty Baxter, the county emergency services program manager, move slowly through their presentations, stopping for questions from the trustees and a small gathering of residents.

"If we get an inch of rain," Baxter is saying, "it may be days before we can reopen Highway 24."

Ekarius later adds that Colorado Department of Transportation representatives believe they "can handle a 10-year event. It will potentially be three weeks or a month of cleaning [U.S. Highway 24]. But they think the highway would survive a 10-year event.

"They will tell you that if it's a 25-year event, they do not believe the highway will survive.

"It would probably not survive from Sand Gulch [above Cascade] to 31st Street. We would be looking at replacing four lanes of highway."

Aside from experience with other fires, most of what is known about how Waldo will flood is based on two documents: a Federal Emergency Management Agency 100-year flood map, and the U.S. Forest Service's Burned Area Emergency Response (BAER) Study. The latter is an initial assessment of the flood dangers and other issues stemming from the burn scar. It was released July 20.

Though it doesn't consider the burn scar, the flood map's topography provides a decent guide to where water might flow once it reaches populated areas. It shows a thick strip of blue covering buildings all along Fountain Creek, from Green Mountain Falls down through western Colorado Springs. Camp Creek looks like a mighty river running over countless homes in Pleasant Valley, near 31st Street. Near where Camp and Fountain creeks meet, the Red Rock Shopping Center is drowned, as is a mobile home park.

To the north, a swelled North Douglas Creek sideswipes buildings, and South Douglas Creek swallows quite a few whole. Huge stretches of Monument and West Monument creeks, coming from the northern watersheds, are a grand stripe of blue, endangering anything built near or along the banks.

Again, this is a picture of the storm of the century — or what could have been the storm of the century before Waldo. Now it represents a 10-year storm for areas affected by burn-scar runoff, and it's likely a little conservative.

"We could see a storm that we used to see every 100 years, every 10 years now," Forest Service hydrologist Dana Butler says. "It could be even more frequently, a two-year storm event, something we regularly see."

The BAER study offers some guidance as to why. The first problem, of course, is that there's little or no vegetation to soak up the water, meaning much of it comes rushing down the hillside. Additionally, about 40 percent of the burn area saw "moderate burn severity" in the soil, and another 19 percent saw "high burn severity." The hotter the ground gets, the less absorbent the soil left behind.

But water is hardly the only problem.

The report notes, "The post-fire area has an erosion potential of 13 tons of material per acre for a 10-year storm event, compared to a pre-fire erosion rate calculated at 2.5 tons/acre across 5 major watersheds: Fountain Creek Headwaters, Cascade-Fountain Creek, Garden of the Gods (Camp Creek), West Monument Creek, and Lower Monument Creek."

To put that in perspective, in a 10-year storm, Camp Creek alone could deliver more than 10,000 dump trucks of debris from the burn scar. Fountain Creek could produce even more, and other major watersheds will be similarly clogged.

Zelenok notes that the debris is incredibly destructive. Water naturally weighs 62 pounds per cubic foot, but can weigh double that with sediment. And rocks and trees in fast-moving water can smash into whatever stands in their way with tremendous force.

Also, sediment clogs creeks and drainage ways, leading to more flooding. Colorado Springs stormwater manager Tim Mitros notes that all that water and debris could easily overpower the city's stormwater channels and pipes, many of which were considered undersized before the fire.

"We don't design subdivisions for fires," he says. "So when you have everything burnt, it changes everything."

Disaster scenarios of this kind don't just exist on paper. Ekarius has witnessed the results of other major Colorado fires, though none was so close to a major population center. She's cleaned up after the Hayman, Snaking, Schoonover, High Meadows and Buffalo Creek fires.

"We've seen flooding in every one of these burn areas, and it's always mind-boggling at first," she says.

Buffalo Creek, the first of those big fires, scorched Jefferson County in 1996. Ekarius remembers that within the first year and a half there were more than a dozen 100-year flood events in the area, including one that killed two people and moved buildings. The creek there, which normally ran at about two to three cubic feet per second (imagine a cubic foot as a basketball), swelled to greater than 2,000.

Years later, she says, workers were mitigating the Hayman burn. NOAA issued a storm warning and the workers took a few minutes to pack up. When they looked up, the dry gulch below was two feet deep and 20 feet across.

"To me, the real news of these fires is what happens after them," she says. "The fire did a tremendous amount of damage. But we're not done with this fire for decades."

Getting out

Given that storms involve many variables, it's tough to determine exactly how much time people may have to seek higher ground. But there are some rough estimates.

Magnuson says that in a large storm, communities like Cascade, Green Mountain Falls and Chipita Park could get less than 10 minutes' warning before water, choked with sediment and debris, thrashes through town. By comparison, from the upper stretches of Queens Canyon, Camp Creek might take 90 minutes to deliver stormwater into the Pleasant Valley neighborhood.

Magnuson says populated areas along North and South Douglas Creek and Monument Creek would likely get less planning time than that, though it's hard to say how much less. Similarly hard to pin down is Manitou Springs, where water from several major watersheds converges. Most of those watersheds feed Fountain Creek west of town, but Williams Canyon Creek hits the town from the north end, running through a culvert under residential and commercial areas before meeting Fountain Creek near the town's center.

Storms won't necessarily dump on all the watersheds. But even a small storm in one watershed can do damage, especially if the water falls fast. Magnuson says NOAA will issue a flash flood warning if as little as a half inch of rain falls on the burn scar. It's updating its radar and has installed rain gauges on the scar to help it determine when to send such warnings.

Meanwhile, a new $120,000 study will soon provide better estimates of how quickly water will move into populated areas in a given storm, and how much damage it will do. Dubbed the Flood Plain Inundation Study and paid for by the Colorado Water Conservation Board, the Pikes Peak Regional Building Department, the county, the city and CDOT, it will estimate the speed of flood waters and map where the water, debris and mud will go. The study, which is being performed by Matrix Design Group, will show a range of scenarios based on the location and rate of rainfall.

The more detailed portion of the study won't be out until at least the end of July, but an initial portion, along with a map that's far more accurate than current FEMA flood maps, could be released as early as the end of April. At that point, Baxter plans to host small community meetings in flood-prone areas so residents can get personalized information.

"What people want to do is, they want to look at a map on a wall and say, 'That's my house right there,'" she says. "'What's the danger to my house?'"

Baxter is also planning for the aftermath of a big flood. With other leaders, she's organized groups focusing on incident command; medical and public health issues; debris clearance; and mass care (think staffing and setting up emergency shelters, arranging bus transportation, and helping evacuate and care for pets).

Meanwhile, the city is planning an April media blitz to tell people what to do in case of a flood (chiefly, get to higher ground). Experts say residents must be proactive because in most areas, police and firefighters won't be able to knock on doors if an evacuation is needed. Only Manitou Springs has sirens, and even those are effective in just a limited area, close to Fountain Creek.

So people in flood-prone areas should sign up for reverse 911 notifications (text and e-mail are the most reliable), buy weather radios (designed to wake a person from sleep), and keep an eye on weather reports. And they should also have a 72-hour emergency kit that can be grabbed easily on the way out the door. (See: "High and dry," p. 22, for more tips.)

Bret Waters, Colorado Springs' Office of Emergency Management Division manager, notes that not all areas have a heightened risk of flooding, but areas that border the burn scar and those along the major drainages from the burn scar need to be aware of the risk. He's holding community meetings, large and small, to try to alert residents in the highest-risk areas.

"It will even involve a door-to-door campaign, believe it or not," he says. "... There are certain areas we're concerned about, so we're going to target those areas, all the way to leaving information for them at their residence."

Digging our way out

Even as some are preparing for the flood, others are working to prevent it. Like no other issue since the fire, the fear of flood has brought governments and agencies together to plan, including: the City of Colorado Springs, El Paso County, federal legislators, Manitou Springs, NOAA, the U.S. Forest Service, the Coalition for the Upper South Platte, AmeriCorps, Colorado Springs Utilities, the Pikes Peak Regional Building Department, CDOT and others.

One team, led by Waters and County Commissioner Clark, is putting together a huge spreadsheet of area projects, including information on likely funding. "I think it makes our case better for us to be able to get [grants] if we're coordinating this," Clark says.

Not that anyone is waiting to start work. The city's Mitros recites many projects off the top of his head. In Queens Canyon, chain-link-like fences have been laid into the creek to catch some of the debris in the water. Downstream, the ditch along 31st Street has been scrubbed clean.

Flying W Ranch has a new series of drainage ponds to slow water and catch debris. Below the ranch, in the Mountain Shadows neighborhood, a detention pond was built, then deepened to catch increased flows.

Manitou Springs has removed large trees that once hung into Fountain Creek, along with some underbrush. Near the old Penny Arcade, the city has doubled the size of its storm drains.

Colorado Springs Utilities is busy fixing its broken pipeline, stabilizing drainages above it, and repairing the access road that's used to reach it, which was damaged by the July 30 storm. It's also built catchment basins in West Monument Creek, and plans more, in an effort to protect a water treatment plant. It will spend around $10 million on burn-related projects this year.

CDOT is spending nearly $4.8 million on projects along U.S. 24, which are expected to be completed in early summer. The department will strengthen the retaining walls near Rainbow Falls, and build structures to contain debris in large slide areas like Sand Gulch, which collapsed July 30.

Meanwhile, logs have been dug into hillsides to terrace slopes throughout the burn scar, sandbags have been slapped down, and mulch has been dropped from helicopters. Smaller projects abound.

Still, much more needs to be done. The process has been slowed for a few reasons, chiefly money. While some grants, local government funding, volunteer work and money from CDOT and Utilities have made a dent in the problem, most mitigation work needs to be done with Emergency Watershed Protection money from the federal government.

The Waldo fire has seen just $1.2 million of EWP funding, though leaders have asked for $9.6 million more. (That figure includes local match money.) Despite advocacy on the part of U.S. Sens. Michael Bennet and Mark Udall, and Rep. Doug Lamborn, the funding had remained elusive as of press time.

The Senate passed a bill addressing Hurricane Sandy relief that also included EWP funding for fire-ravaged areas last year, but the House let the bill expire Jan. 2, then wrote a new bill that excluded the funding. The latter passed both houses and was signed into law.

The exclusion of fire and flood funding upset Bennet, who came to visit the new sediment basins on Flying W Ranch on Feb. 22.

"It's all being done in the name of being prudent financially," he said. "This is what is prudent, is actually getting it done."

The House has since passed a bill that includes $48.2 million EWP funding for projects across the country, and the Senate included $65.5 million of the funds in its version of the bill. If either version of the bill passes and is signed into law, Waldo is likely to get much of the money it requested, says Kristin Lynch, Bennet's spokesperson.

Meanwhile, the Colorado Watershed Conservation Board, CDOT, the Forest Service, the city, the county, Manitou Springs and others have jointly funded a $475,000 Watershed Assessment of River Stability and Sediment Supply (WARSSS) study.

The WARSSS, required by the U.S. Environmental Protection Agency and scheduled for release at the end of March, will predict how water, sediment and debris will move along and off the burn scar. Based on its findings, it will provide a list of prioritized mitigation projects.

Baxter says a lot of major work awaits that study.

"Our concern is that if we were to rush in and put treatments in before that assessment is over, we'd spend a lot of time, money and effort putting a treatment in, only to find we put it in the wrong place, or we put in the wrong treatment," she says.

The WARSSS is being performed by Fort Collins-based hydrologist Dave Rosgen, considered top in the field. He and his team have walked more than 70 miles through the burn scar in order to map the area and understand the conditions.

"It's not simple; it's a complex system," Rosgen says. "But I try to make it — now [that I have] 48 years in the business— make it simple."

Rosgen notes that only five or six projects are likely to get done this summer; it will take years to implement all his recommendations. And even when the projects are complete, the risk of flooding won't disappear, especially for homes in the floodplain.

In nature, Rosgen explains, creeks flood in a fan outward, dropping their sediment, but that natural process doesn't work nearly as well when homes and businesses lie in the way. And in Colorado Springs, where water has long been scarce and treasured, we've built heavily along our waterways.

Unfortunately, he says, "We can only encroach so far against the channel, before it encroaches back."


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