Project: The West Fraser Road (WFR) Flood Recovery Project
Client: MOTI, Southern Interior Region
Background: The Narcos Creek Bridge on the West Fraser Road is approximately 20 km to the south of Quesnel on the west side of the Fraser River. The Ministry of Transportation, Southern Interior Region retained Binnie to provide highway design, drainage design, and coordination for the West Fraser Road (WFR) Flood Recovery Project. The end goal of the project is to replace the existing road that follows Narcosli Creek with a new road alignment, avoiding the creek as much as possible.
Scope of work: Binnie’s project scope of work includes the following: design of a new roadway alignment to 80km/hr. standard, wherever possible (completed), improvement to the Horizontal and Vertical alignments (completed), drainage works including the drainage of the roadway, Winnie Creek, existing overland flows, and the final stage which is the new bridge structure (design completed, construction underway).
The WFR Project began in May 2018. The spring freshet had washed out five locations along the West Fraser Road, which forced the closure of the West Fraser Road and prompted a detour route along Webster Lake Road and Garner Road. Binnie and Geonorth recommended a new alignment instead of reinstating the existing road due to the risk of future washouts. Soon after that, the 2020 freshet caused further damage to all existing washout sites, validating the decision to do a new alignment instead of reinstating the road. The significant number of washouts and landslides along the creek resulted in removing entire sections of West Fraser Road.
As a result, detours were introduced, adding approximately 60 minutes of travel time for the 200 vehicles that used the road every day and impacting Buck Ridge and ʔEsdilagh First Nation residents. The urgency to realign the road became a priority because West Fraser Road acts as the detour route for Highway 97. If both routes were simultaneously blocked, the detour route would result in a 9+ hour detour for drivers.
Solutions to address the road recovery involved the realignment of approximately 5 kilometres of the West Fraser Road to avoid five large washout areas and 3 km of historic slides along the existing road alignment. The project realigned West Fraser Road onto the other side of the creek. This new road alignment required extensive coordination for rock excavation, large embankments, and a new bridge.
Additionally, the aggressive topography and extensive geohazards throughout the corridor made finding a safe, constructible, and affordable road realignment challenging. Binni’s team prepared numerous design iterations before arriving at the final alignment selection. The aforementioned freshet of 2020 caused extensive damage both upstream and downstream of the proposed bridge crossing. It also prompted a complete redesign of the bridge crossing and road approaches as project phases were nearing completion in June 2020.
As of Spring 2021, the design portion of the project has been completed, with construction underway for the new bridge structure and road alignment. The design of a new roadway alignment and improvements to the horizontal and vertical alignments will allow the local communities to return to their historic route. This removed their need to drive on a 40+ minute gravel detour to drive to Quesnel.
Freshet: the flood of a river from heavy rain or melted snow