It’s time to start thinking about the potential risks of flooding from spring runoff on the 416 Fire burn scar.
This winter’s snow has been a welcome sight to drought-stricken Southwest Colorado. As of Tuesday, the Animas, Dolores, San Juan and San Miguel basins were at 125 percent of normal, historic averages.
But with all that snow comes the risk of flooding and debris flows into homes, structures and roads adjacent to the 416 Fire burn scar.
Last July and September, heavy rains brought devastating flooding to homes north of Durango, in and around Hermosa.
Lindsey Hansen with the U.S. Forest Service told a crowd of about 60 at the Animas Valley Grange on Tuesday night that there are steps to take to help mitigate the impacts of the 416 Fire, but it’s tricky when it comes to protecting private property.
The Forest Service is tasked with repairing trails, managing invasive plants, removing downed bridges and cleaning out sediment ponds, among other measures needed in response to a wildland fire.
But placing diversions above homes to protect them from flooding hasn’t proved effective from stopping debris coming down.
“It’s a hard answer to give that we can’t just stop it from happening,” Hansen said. “But the way our topography is, that’s the situation.”
Soils burned in fire no longer have the ability to hold water. So when it rains or snow melts, a torrent of debris, mud and ash can form and be devastating to anything in its path.
But, there are encouraging aspects about the 416 Fire.
According to the Forest Service, only 3 percent of the estimated 54,000-acre fire burned at a high severity, which means there’s less of an area that could cause problems to property and water quality.
Areas that didn’t experience extreme burn temperatures are better able to recover with vegetation, which stabilizes the soil.
Also, the upper reaches of Hermosa Creek were spared in the fire, giving aquatic life a better chance to rebound.
Scott Roberts, an aquatic ecologist for Mountain Studies Institute, said studies of wildfires across the country have shown waterways recover within one to 10 years, with three to five years being the average.
“We’ll probably have more debris flow,” Roberts said, “but I’m hoping we’ve seen the worst.”
This all depends, of course, on the weather, Roberts said. If runoff or a storm hits a particularly vulnerable area, there could be intense flooding.
Hansen said the main stem of Hermosa Creek is sometimes able to dissipate flooding because of its wider river banks. But other side streams, such as Tripp and Falls creeks, are narrower shoots, and it’s there flooding can happen quickly and be damaging.
“(Tripp Creek) is one of our biggest concerns,” she said.
Hansen recommended anyone with concerns about flooding contact the Natural Resources Conservation Service, the federal agency able to help private landowners.
Roberts said Mountain Studies Institute will continue to monitor Hermosa Creek and the Animas River during and after spring runoff.
Below the confluence of the two waterways in July 2018, a surge of ash-laden runoff killed nearly all the fish. But Roberts said more tolerant aquatic bugs were able to survive, and already, the river shows signs of recovering.
“We need fire on the landscape,” Roberts said, “but unfortunately ... they can be devastating to private property.”