Rock slides, cave-ins, and instability close area highways
By Patty Unruh
As every Colorado resident is aware, 15 counties in the state were inundated with rain in a historic flood, as Denver and surrounding areas received more than their annual rainfall in just a few days. Scenes of washed out roads, cars in creeks, and submerged homes and businesses became common. Several deaths were reported, hundreds of people unaccounted for, and about 20,000 homes damaged or destroyed. Gilpin County residents fared somewhat better than many of our fellow Coloradans, with inconvenience due to road closures the main issue.
Gilpinites were cut off from access to the metro area from periodic road closures. Gilpin County Sheriff’s principal information officer Cherokee Blake stated on Friday morning September 13, that “Gilpin is an island. Not because of flooding here, but because highways 46, 6, 72, and I-70 are all closed due to rock slides and flooding downhill.” Later that morning, Highway 6 was open again, but Blake advised to expect delays. She said there had been no reports of damage to homes or other similar problems. Over the weekend, travel on Highways 119 and 6 was fairly smooth, although heavy with extra traffic.
Work progressed over several days to reopen highways, but with continued rain and potential rockslides and instability, roads could close again with virtually no notice. Highway 46 was closed when portions of the canyon walls began hanging over the roadway. The road will be closed, or reduced to one lane in sections, for several days until the instability can be resolved. Blasting commenced last Saturday as engineers began addressing the problem. The Gilpin Sheriff’s Office had no estimate of when the highway would be reopened fully.
The City of Black Hawk advised that there had been numerous rock slides on the highway, as well as a rock slide on Chase Street, but that Public Works was cleaning up the slide. No flooding was reported by the casinos. Melissa Greiner of the City Manager’s Office said the river walk behind the casinos had been closed. She also had received no reports of damage.
Another issue was the loss of DSL internet service to many county residents for several days, as well as the loss of telephone service.
Unofficial rainfall totals included 4 to 5 inches in Black Hawk and about 9 inches in mid-Gilpin County as of last Sunday. Our area had already received several inches of rain during the summer, saturating the ground so that water ran off rather than soaking in.
Many mountain roads in the state were damaged, along with roads and bridges throughout the 15-county area.
Neighboring Coal Creek Canyon was especially hard hit, with more than 14 inches of rain and washed out roads.
Nederland received over 12 inches of rain.
Access was closed to downtown Evergreen from the bridge to Meadow Drive due to water over the road; area buildings were being assessed for damage. Two access bridges to Highway 74, Forest Hill Bridge and Independence Trail Bridge were closed, and being assessed for safety.
From September 9to 15, rainfall totals ranged from nearly 5 inches in the metro area to more than 18 near Boulder, where rushing water, debris, and mudslides made mountain roads in Boulder Canyon and other canyons west of the city impassable. Thousands of people had to evacuate the area.
Lyons was cut off, with flooding, washed out roads and bridges, and several hundred people evacuated by the National Guard.
Colorado was declared a disaster area, with the size of the flooded area growing daily. Flooding impacted the foothills from Fort Collins south to Canon City, 180 miles away. Floodwaters spread east to the plains as well. Amy Ford, a spokesperson for Colorado Department of Transportation, advised USA Today that the damage will cost hundreds of millions of dollars to repair.
The unusually heavy rainfall over our terrain of mountains and canyons channeled water down through the foothills. The rain came from a strong, slow-moving storm from the west, combined with monsoonal air coming from Mexico.
Many Gilpin residents will also recall the Big Thompson Canyon flood of 1976, one of the worst natural disasters in Colorado history, which killed 144 people downstream from Estes Park. The Lawn Lake Dam flood of 1982 killed three people, caused $31 million in damage to Estes Park, and created an alluvial fan of debris in Horseshoe Park.