Abstract Manager

Kicking Horse Canyon Project – Phase 4 (KHCP4) includes approximately 4.8 km of Trans-Canada Highway (TCH) widening to two lanes in each direction. The Project site is located approximately 5 km to the East of Golden, BC in a mountainous area with relatively dense forest coverage and steep slopes. Runoff generated uphill of the highway is conveyed through highway drainage infrastructure towards the Kicking Horse River. Existing culverts and ditch system convey flow along the highway; however, proposed bridges and viaducts were required to accommodate highway widening and this was limiting the installation of new culverts or replacement of the existing culverts.

Drainage like all other highway design disciplines in the mountainous area is challenging where multiple stakeholders are impacted. Clear and up to date guidelines in era of climate change could improve the design and result in a more robust and reliable system that will provide service for decades to the public. The proposed drainage design has been developed to accommodate forecasted runoff with the expanded highway footprint, while avoiding the concentration of flows and increase in peak flows to Canadian Pacific Rail (CP Rail) existing drainage infrastructure at downslopes.

KHCP4 was a design-build project bound by Design-Build Agreement and available Federal and provincial Guidelines and Technical memorandums. Existing guidelines addresses most of design requirements, but considering BC’s vast geographic and topographic variation more needs to be done. Issues like rain-on-snow and debris flow are not addressed in highway or drainage guidelines clearly and leaves the design to engineering judgement and available research. KHCC worked in close collaboration with the Province and CP to address different issues including Project impact on CP Rail, climate change requirements, debris flow and highway drainage by employing more complex hydrologic and hydraulic modeling. Project was received substantial completion in November 2023 and it provides a safe 4-lane highway for the public.