From The Colorado Sun (Sue McMillin):
Even a quarter inch of rain pouring onto those devastated slopes could bring a new disaster to hundreds of homes and businesses in the Cucharas River valley, including the towns of La Veta and Walsenburg.
The 1,000 residents of La Veta could have as little as 30 minutes warning of a flash flood, and in a worst-case scenario the town could lose 70 percent of its structures.
“We believe we’re going to lose homes,” La Veta Mayor Douglas Brgoch said. “We believe we’re going to lose access and so forth. We don’t want to lose any people.”
Walsenburg’s 3,000 residents would have more warning time, but the potential for devastation also is severe — as many as 600 homes could be flooded along with City Hall and the county’s emergency operations center (a backup location has been secured).
The La Veta town hall also is in “the crosshairs of where flooding would be.” Officials would move to the water treatment facility that is on high ground, Brgoch said.
Town and Huerfano County websites are chock full of flood preparation information. Sirens and stream gauges have been installed, channels cleared and sandbags filled.
In La Veta, residents who live uphill from flood danger have signed up to be “flood buddies,” offering their homes as refuge to friends and neighbors whose homes are most endangered.
Army of volunteers help keep resources focused
About 160 people have put in more than 2,000 volunteer hours with the La Veta Trails organization to clear debris and brush from the banks of the Cucharas River where it runs through town…
Volunteers with Walsenburg’s newly hatched Green Leaf Committee have been doing the same thing along the river banks in that town.
Numerous government and nonprofit agencies are pitching in, coordinating through a post-fire flood task force. Huerfano County Emergency Manager Larry Sanders tried to tick off a list of those who’ve contributed money or services or both: Natural Resources Conservation Service, AmeriCorps, U.S. Forest Service, Army Corps of Engineers, Colorado Department of Natural Resources, U.S. Geological Survey, National Weather Service, Colorado Department of Transportation, water districts, local nonprofits. His voice trails off…
Given the potential for a life-threatening flood — not just this year, but for several — Sanders said everyone keeps pushing to complete as much preparation as possible before monsoon season, typically mid-July to September. But they’ve also warned residents that any spring storm with heavy rain could lead to flooding.
The region got a taste of the potential after the fire last summer, with 13 flood warnings and a “few” events that caused some damage. They lost some cattle, barns and other out buildings and a couple of county roads washed out, he said.
But he anticipates much worse flooding from the burn scar.
“It’s not if and not even really when, but how many times,” he said.
Burn scars statewide are prone to flooding for years
The residents of Huerfano County are not alone. Hundreds of thousands of acres in Colorado have burned in wildland fires this century, often leaving burn scars prone to flooding for years.
A mud and rock slide from the 2002 Missionary Ridge fire near Durango recently closed a county road. Flash flood warning signs dot some canyon roads through the 2002 Hayman Fire burn area, where charred tree trunks stand starkly on the landscape. Closure gates and flash flood warning signs on U.S. 24 through Ute Pass are a reminder of the deadly flash floods that followed the 2012 Waldo Canyon Fire.
Depending on the intensity and size of the fire, the steepness of the slopes and its proximity to watersheds and population areas, the results can be catastrophic.
Weston Toll, a watershed program specialist with the Colorado State Forest Service, said burn scar runoff can be devastating to reservoirs, agricultural land and rivers downstream as well as to homes and other structures. Special Burned Area Emergency Response (BAER) assessments are completed to help predict post-fire flooding risks.
The intensity of a fire is key because it is so hot that the soil is sterilized, regrowth — and therefore erosion control — takes much longer. Nearly a quarter of the Spring Creek Fire acreage burned at high intensity, according to the BAER report.