A critical connection reshaped by flooding
In November 2021, an atmospheric river triggered widespread flooding across southern British Columbia, reshaping rivers, washing away highways and isolating communities. Along Highway 8 between Spences Bridge and Merritt, the Nicola River carved a new path through the valley, damaging multiple locations along the corridor and severing a vital transportation link for residents, Indigenous communities, emergency services and local businesses. Rather than simply rebuilding what had been lost, the British Columbia Ministry of Transportation and Transit (BC MoTT) launched one of the province’s largest highway recovery programs. The project not only restored access but rebuilt the corridor to withstand the increasingly severe floods expected in the future.
After the flood, the Nicola River no longer followed its previous course. The river widened, shifted its banks, disturbed riparian vegetation and altered fish habitat. Severe erosion at Sites 9 and 10 made it impractical to restore the highway along its former alignment. As an interim measure, temporary single-lane bridges were installed, and a section of highway was built on the opposite side of the river while our Onterris project team designed the permanent bridges and about 3km of highway for this new alignment.
The BC MoTT needed permanent bridges that could restore dependable two-way travel while responding to the river’s new conditions. The crossings also needed to account for future floods, erosion, debris, sediment and ice.
Designing climate-resilient bridges for future floods
Onterris supported the permanent bridge replacements and associated road and bank protection work through the Nicola Valley Partners Alliance. Hydrotechnical, environmental, geotechnical, structural and transportation expertise, along with knowledge shared by Indigenous communities, helped inform solutions that balanced river processes, habitat considerations, constructability and long-term resilience.
The team used the 2021 record flood as a starting point for designing more resilient infrastructure. Each bridge was engineered to withstand a larger future flood and remain stable even if an extreme event damaged sections of the approaching roadway.
Deep pile foundations extend well below the riverbed and predicted scour depths, providing the structures a strong and stable base. Longer bridge spans provide more room for the river to move beneath the crossings, while increased bridge height adds clearance for higher water levels and floating debris.
Hydraulic models are valuable tools, but effective river engineering requires more than modeling. It requires understanding how a river has behaved in the past and using sound engineering judgment to anticipate how it may evolve.
Integrating river engineering and fish habitat protection
Resilience extended beyond the bridge structures. The team integrated environmental enhancement into bank protection design by integrating large woody debris and boulder clusters that provide shelter for fish and diverse flow conditions for salmon and other aquatic species. Temporary working platforms in the river allowed crews to complete the work while limiting disturbance to the river and surrounding aquatic habitat and respecting environmental timing windows.
By working closely with environmental specialists, bridge designers, transportation engineers and drawing on knowledge shared by local and Indigenous communities, we developed practical solutions that balance river processes, aquatic habitat, flood resilience, constructability and safe, reliable transportation along Highway 8.
A model for climate-resilient recovery
The two permanent bridges opened in December 2025, replacing temporary crossings with infrastructure designed for long-term travel and more severe environmental conditions.
The project shows how post-disaster recovery can look beyond replacement. By accounting for higher flows, channel changes, sediment, debris and ice, the new crossings respond to the risks that communities and transportation authorities increasingly face.
The completed bridges now provide a more reliable connection for the Nlaka’pamux people, other Indigenous communities, ranches and property owners along Highway 8. They also offer a practical model for rebuilding critical infrastructure around changed landscapes rather than outdated assumptions. As the Nicola River continues to evolve, the Highway 8 crossings are positioned to support community access while working with the conditions that will shape the corridor.
The project was recognized with a 2026 ACEC-BC Award of Excellence, demonstrating the value of resilient design in post-disaster infrastructure recovery.