ITD crews were on scene with cameras rolling as a hillside broke free and covered a section of U.S. 95 south of Bonners Ferry on Friday, April 7.
In the video, you can see tons of mud, rocks, and trees slide down, pushing two layers of concrete barriers off the road. Overall, 800 cubic yards of debris slid onto the road.
Thanks to quick action of ITD crews on scene, no one was injured by the slide. ITD Land Surveyor Mathew Wilson, who took the video, was assessing the hillside stability. He heard popping and cracking and knew another slide was imminent. Thinking quickly, the flaggers on scene stopped traffic and just three minutes later the hillside gave way.
ITD crews cleared the debris from the road Friday evening. Additionally, crews dug out an extra 600 cubic yards of dirt beside the road to create a channel for water to run.
Currently, ITD is keeping one lane open on this section for the safety of the traveling public. Cars will travel on the southbound lane, away from the hillside. Flaggers will direct traffic and actively monitor the area.
This section of hillside continues to be unstable. Crews have noted progressive shifting near U.S. 95. Rain is in the forecast and there remains 18 inches of snow above the slide area. ITD is working with geology specialists to assess the situation. With public safety as a priority, additional traffic control measures may be taken.
Several areas of North Idaho are impacted by this year’s historic winter precipitation. Slides have occurred on Idaho State Highways 3, 5, 57, and 97.
Completing a new temporary route east of Plummer and west of St. Maries earlier than expected, the Idaho Transportation Department has given motorists a detour around a section of Idaho State Highway 5 recently decimated by moisture under the road and slides.
The new 500-foot-long route opened in time for the morning commute Wednesday, with temporary signals at each end of the route guiding traffic. A solid concrete guardrail will be placed on the edge to safeguard drivers.
Work on the temporary route began last Thursday. Crews placed a rock base, rolled it to compact the base, and placed a layer of top fill gravel and dirt on top.
To provide a smoother surface for drivers and protect the new temporary route around Idaho 5 between St. Maries and Plummer, Idaho Transportation Department crews will pave the new 500-foot-long temporary route Friday night (March 31) with about 2.5 inches of asphalt.
The paving will start at 8 p.m. Friday and finish by 3 a.m. Saturday. This timeframe as chosen because it will impact the fewest travelers, as the lowest traffic volumes are overnight.
The temporary route will be completely closed during this paving. Detour routes are Idaho 6 to the south, connecting with U.S. 95, or Idaho 3 to the north, connecting to Interstate 90.
The temporary route will remain in place as Idaho 5 is rebuilt over the next several months. The larger reconstruction will likely last through mid-summer, but will not begin until geologists make a determination on the stability of the road area.
Shifting ground from a very wet spring has caused sections of State Highway 5 to heave and collapse.
ITD has completely shut down ID 5 between Parkside Rd. and Conklin Park Rd. A mud slide beneath the road has caused it to crack and sink. In some areas, the road is gone entirely. At this point in time, engineers fear the section of road may be a total loss.
Crews will start to do exploratory drilling Friday and into the weekend. This will help discover the extent of the slide and what repairs may be needed once shifting stops.
ITD first noticed significant damage last Monday. Initially, small 3-inch wide cracks formed on the road surface. By Tuesday those cracks were 8 inches wide and more than six feet deep. Since then the road has steadily deteriorated and continues to shift.
Motorists are advised to detour around the dangerous area. ID 3 and ID 6 are the best options. Local traffic has been using the state park road, but that is now restricted due to unstable ground. Local authorities are asking those roads be used only for local emergency traffic.
As winter weather continues in the region, drivers in north Idaho are now seeing blue as ITD maintenance crews begin using a new blue salt product. The new salt may represent the next stage in the department’s efforts to improve road-clearing efforts and resulting public safety.
According to the manufacturer, Saltworx, the blue salt is less corrosive than traditional salt, and less of the new blue salt is needed to achieve the same results that traditional salt can provide, so it is potentially a cost savings as well.
“We are just experimenting with it at this stage, but it has the potential to save money, some wear-and-tear on vehicles, and most importantly, be more effective on the roads,” said ITD’s north Idaho management assistant, Mike Lenz.
The new blue salt will be used on 1,500 miles of area roads across the region.