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— Slip-slidin' Away —

Rain-drenched hillside bathes Idaho 55 with mud, debris

A mudslide on Idaho 55 closed the highway north of Banks for 49 hours, starting at 7 p.m. Thursday (Sept. 5). The slid occurred near Zimmer Creek where a fire a few years earlier left the hillside without any vegetation or roots to help “anchor” the rocks and dirt and absorb the rainfall. The saturated hillside deposited mud, rocks, trees, and other debris. The slide swept across the road with enough force to push guardrail out of place.

ITD responded with a pair of excavators, a fleet of trucks and multiple loaders. By the time the weekend was over, Banks/Cascade Maintenance Foreman Brian Inwards estimated crews had moved more than 5,000 cubic yards of debris – with each cubic yard weighing between 1,500-2,000 lbs.

ITD could not assign every maintenance resource to the Idaho 55 clean up, however, as Thursday night’s rain also produced flooding and washouts in the Owyhees, specifically on a 15-mile stretch of Idaho 78. A nine-man crew with dump truck, backhoe, grader and a fleet of trucks spent at least 84 man-hours and more than $7,000 to clean up in the aftermath of that event. They added about 120 cubic yards of material along the highway shoulder to fill the void

Some of the rental costs for equipment hadn’t yet been factored in, but by the end of Tuesday (Sept. 10), the cleanup efforts on Idaho 55 had moved 6,700 cubic yards of debris at a cost about $68,000. The response required nearly 1,900 employee-hours. Inwards estimated the cleanup would continue for about a week.