The sinking of Highway 133

Nature is coming for Colorado drivers from all sides during springtime in the Rockies. Commuting in the mountains is like Chicken Little’s version of Russian Roulette with rock slides, mudslides and sinkholes. Coloradans may not have to slalom alligators and roll over Burmese python speed bumps, as they do in Florida, but I contend driving in Colorado is even more precarious.

I once had a snowy owl bounce spread eagle against my windshield, and the deer are practically suicidal. In old-town Carbondale, the side of my car was body-slammed by a deer while I was driving down Main Street. I guess the deer bounded past the Village Smithy in search of forest, leaving my car dented and tufted with fur. Hello deductible.

I developed some resentment toward the “watch for falling rocks” road signs. Craning my neck to see if the sky is falling while driving and attempting to outmaneuver gravity doesn’t seem practical. The two car-sized boulders that blocked my way home on 133 last summer would have hit me like an ACME anvil, no matter if I drove like the road runner. It’s all a matter of chance, and in the springtime, the odds start to favor mother nature. I propose amending the signs to say, “Falling rocks. Drive at your own risk.”

Spring mudslides on 133 near the Penny Hot Springs can be overwhelming. Luckily, the skinny-dipping hippies go elsewhere when the spring runoff washes out their enclave. The new retaining wall seems formidably effective at holding back the oversaturated earth. Sopping soil leads to more abundant surface run-off and heightens the chance of debris build-up and dams. Currently, Colorado is experiencing a sinkhole reminiscent of Florida. Sinkholes can develop anywhere the underlying ground is void, such as old mining tunnels, culverts, or hollow rock formations.

On Tuesday, May 2, a sinkhole forced a safety closure of Highway 133 near Somerset. CDOT has been monitoring the potential road failure around the clock since Saturday, April 29, when the highway started showing signs of buckling. During a 2020 inspection, a hole had been identified in the underlying culvert and was deemed eligible for replacement but was not rated for priority repair or replacement, according to Elise Thatcher, Northwest Colorado regional communications manager at the Colorado Department of Transportation.

The spring runoff and resulting buildup behind a debris flow lodged a large log into the preexisting culvert hole. The hydraulic pressure sheared and propelled the culvert 60 feet toward the North Fork Gunnison River. Unsupported, the roadway eventually collapsed. Thankfully, no one was hurt during the road failure. The ensuing sinkhole continues to erode and is currently three times larger than it was initially.

Last week, contractor Ralph L. Wadsworth won the bid with CDOT in the amount of $1.9 million to install a temporary two-way bridge and repair Highway 133. CDOT has a history of working with this contractor on other projects. The contractor is performing emergency maintenance until the temporary bridge can be erected. Once the temporary bridge is installed, they will begin the permanent repairs and determine a proper structure to replace the culvert, most likely an open-ended concrete box.

CDOT representatives described the temporary bridge being put together like an Erector set (think old-school Legos) and then placed across the chasm. Geo pattern analysts will establish how far to place the ends of the bridge across the sinkhole to ensure the structure is on sound ground. The temporary bridge will resemble a permanent bridge and allow vehicle passage in both directions.

In the meantime, CDOT has identified the 180 residents of Somerset, area contractors and miners through a reverse 911 system. They have been issued passes to skirt around the sinkhole on a small access road to Paonia and Somerset. There is also a temporary bus system to shuttle 300-plus mine workers to and from the mine.

Springtime in the Rockies can be challenging for Colorado commuters, so keep your head and stay alert so you don’t get hurt. CDOT encourages travelers to detour via Highway 50 and I-70. Real-time updates will be posted at COtrip.org