Giving nature room to swing its elbows with floods & mudslides
The Rocky Mountains probably don’t pose the same potential for a massive mudslide as is found in coastal areas of Oregon, Washington, and British Columbia, according to Spenser Havlick, a semi-retired professor at the University of Colorado. The soils are thinner, with rock close to the surface.
Still, interior mountain ranges can have dangers. Cutting into the toe of an unconsolidated mass of soil, as is often done for highways and even residential development, elevates the risk, he says. Glenwood Springs, Colo., has significant issues with mudslides. Vail’s Potato Patch neighborhood is problematic.
In general, it’s best to leave room for nature to do what it will, he tells students in his course, “Thinking Like a Mountain,” a phrase taken from “Sand County Almanac,” the seminal conservation book by Aldo Leopold.
Mountain towns such as Vail and Telluride have done a generally good job of mandating that people can’t build homes in the runoff zones of avalanches, he says.
But in zoning to reduce destruction of property or loss of human life from floods and other natural disasters, communities in Colorado have been less cautious.
Havlick lives in Boulder, one of the towns swamped by last September’s rains that drenched the foothills of the Front Range. While well away from creeks, the basement of his house still flooded.
Boulder’s flooding could have been worse if not for precautions taken several decades ago at the urging of Gilbert White, a CU professor who persuaded Boulder to limit encroachments into flood plains. Boulder could still be devastated by a more significant flood. Basically, its downtown lies in a flood plain.
With the evidence clear enough from this storm, should Colorado and local authorities tell those who lost homes that they cannot now rebuild?
That’s a hard conclusion to give to a property owner, says Havlick, who served on the Boulder City Council. However, it’s a public policy that would make sense in the long run.
“We really should discourage people from building in high hazard zones. Flood insurance does not reflect the true costs. I think the same prudence that we are beginning to give to avalanches should be given to flood planning.”
Colorado is busily trying to get creeks and rivers free of debris so that spring runoff can occur without causing additional damage. The St. Vrain and other rivers and creeks are being rerouted to accommodate the previously installed infrastructure of bridges and irrigation headgates.
Havlick says that he recently heard an intriguing idea. Instead of trying to avert possible floods this spring, maybe the best long-term solution would be to let the creeks and rivers rampage a little bit more, to be clear about where they want to run. Then, with that known, give those waterways those wider berths.
Has Colorado learned any lessons from these floods? At this point, it’s hard to say. The attraction of living along a river is a powerful one, and our memories are short.