The county has opened bidding for the construction of the Evans Riceville Road repair.
Bids are due by 3 p.m. Oct. 27, when they will be opened, and will require approval by the County Commission.
The project consists of repairing a road slide, including 10 feet of excavation of poorly compacted road subgrade, reconstruction with structural fill and geogrid, surfacing gravel, magnesium chloride treatment, slope regrading and revegetation with geoweb stabilization, according to county documents.
A pre-bid conference is scheduled for 1 p.m. Oct. 20 at TD&H Engineering.
In September, Cascade County Commissioners approved a $59,900 contract to TD&H Engineering for engineering services for the Evans Riceville Road repair.
County approves engineering contract for Evans Riceville Road slide repair
A significant road slide occurred on June 1 about four miles west of Highway 89, requiring closure of the road due to continued movement and unstable soils beneath the roadway.
On Aug. 27, the county reopened the portion of the 1890s alternative Evans Riceville Road that was previously closed by the landowner.
County opens alternate Evans Riceville Road as repair effort continues
The county intends to use the 1980s alternative Evans Riceville Road for public use while repairs are made on the current road, built in the 1960s, where the road slide occurred.
The county is posting regular updates on the project here.
The current roadway remains closed due to safety conditions created by the slide in early June after significant rainfall.
County staff reviewed historical records and available information to determine that the 1890s alternative road was not abandoned and remains a county road open to the public.
After the June road slide, county public works staff worked with engineers and others to get soil samples and better understand the road conditions.
During that process, staff determined that professional engineering services would be required to evaluate the road and develop a repair plan.
The county then determined that an immediate land survey was needed before engineering design could be done to verify the existing road rights-of-way and property boundaries around the slide area.
The county received preliminary geotechnical investigation results in early September and based on those results, determined that the road will not be reopened to one-lane traffic.
“The engineering investigation indicates that the original failure was largely driven by moisture conditions within the roadway embankment. The investigation also identified standing water near the base of the existing roadway materials, even though there had not been recent rainfall at the time of the investigation. This indicates that stormwater may be traveling through and accumulating within portions of the roadway embankment,” according to the county.
The engineer determined that weather and stormwater are greater concerns than traffic since the existing slide weakened the roadway embankment, leaving a substantially steeper face and while the slope appears stable under dry conditions, that stability is variable and weather-dependent, according to the county.
Moving into winter with more storms and moisture, the engineer found a significant possibility that the slide could “progressively fail and take additional portions of the roadway with it,” according to the county and recommended that the road remain closed until repaired.
Les Payne, county public works director, told The Electric in late August that he signed a contract with TD&H Engineering on July 30 for surveying work in the area, which was needed to proceed with the project regarding the right-of-way and road layouts.
Evans Riceville Road closed indefinitely due to slide
Payne said due to timing and the contract amount, it didn’t need to go before the County Commission.
In July, the county solicited for engineering services, receiving one bid from TD&H.
During the Sept. 2 work session, Payne told commissioners they’d done some surveying and drilling, which had to be done to get to the engineering step.
Evans Riceville Road restricted to one lane due to slide
He said he’d spoken with the drillers the day before and conditions weren’t as bad as expected, so he’s hopeful the repair won’t require a wall structure, just geotechnical work and drainage.
Payne said that depending on soil testing results, the county may be able to reopen one lane of the current Evans Riceville Road.
*County public works photo
