We have identified three slopes on US 97A between Entiat and Chelan for this rock scaling work, at which a contractor will be removing the loose rock on the slopes and hauling it away to a disposal site.
During the rock scaling work, the roadway will need to be closed for the safety of the workers and the traveling public. When the contractor is removing the loose rock, the rock will fall down onto the roadway and will be removed before the roadway is reopened for traffic.
While the roadway is open for traffic, our contractor cannot be removing rock. The more traffic openings that we have, the more working days it will take to remove the loose rock.
During a similar project on this roadway in 2012, the feedback we received from the public supported the project traffic control to provide three 30 minute mid-day openings for traffic, but otherwise closing the highway during the day to complete the work. The working days listed below are based on this suggested road closure option. Other closure patterns will change the estimated days required to complete the total project.
The first slope is located at MP 217.62 to MP 217.68, between Entiat and the US 97A/Navarre Coulee Rd intersection. At this location, we are expecting to remove 700 cubic yards of material, which is about 70 dump truck loads (10 cubic yards equals about one dump truck full).
It is estimated that work on this section will take nine days to remove the rock, which means that there will be approximately nine days of roadway closures at this location.
The second slope is located at MP 219.80 to MP 219.90, which is between Entiat and the US 97A/Navarre Coulee Rd intersection. Here, we estimate a need to remove approximately 500 cubic yards of material, or about 50 dump truck loads. It will take approximately seven days to remove the rock, meaning that there will be approximately seven days of roadway closures at this location.
The third slope is located at MP 224.09 to MP 224.13, which is between the US 97A/Navarre Coulee Rd Intersection and the Knapps Hill Tunnel. At this location, we are expecting to remove 150 cubic yards of material (about 15 dump truck loads). It will take approximately two days to remove the rock and require about two days of roadway closures at this location.