Highway 37 Culvert Replacement and Fan Re-activation
NHC has supported the British Columbia Ministry of Transportation and Transit through a multi-phase project to improve the resilience of the Fan Creek and Revision Creek culverted stream crossings along Highway 37 in northern British Columbia. Both crossings are routinely de-stabilized by heavy debris and sediment loads. The work began with geomorphological and hydrotechnical assessments by NHC, then progressed through multi-disciplinary concept development, design basis development, and detailed design for replacement structures. Both replacement projects are currently under construction.
BC Ministry of Transportation and Transit
Streams & Rivers
Northern British Columbia
During the initial assessment phase, NHC completed watershed and reach scale geomorphological and hydraulic investigations to understand the processes affecting sediment transport and deposition. Prior maintenance practices resulted in the construction of high berms on both banks of the creek downstream of the culverts, which led to rapid, vertical build-up of sediment and loss of hydraulic capacity at the culverts.
Using hydraulic and sediment transport modelling, NHC assessed multiple replacement alternatives and developed hydrotechnical design criteria to support future upgrades. The studies evaluated culvert, bridge, and hybrid (very short span bridge) crossing options, along with unique sediment management strategies intended to reduce long-term maintenance requirements. The work established hybrid bridges as preferred structural concepts along with a naturalization of the alluvial fans downstream of the highway – in other words, allowing the creeks to wander and spread sediment laterally, as they would have done prior to highway development. At Revision Creek, an “off-line” protective berm works has been incorporated to safeguard transportation and utility infrastructure from future channel avulsion activity.
Delivered a complete hydrotechnical services package including assessment, concept development, detailed design, and services during construction. A unique “outside-the-box” solution will address the significant sediment maintenance issues facing MoTT, and improve the safety and long-term reliability of this Highway 37 infrastructure.
