Balancing Flood Conveyance and Fish Habitat Design in a Steep Urban Stream: A Case Study of the Penticton Creek Restoration
James Bigelow
Stantec Consulting, Inc.
Calgary, Alberta, Canada
Penticton Creek is a steep, urban creek within the City of Penticton, British Columbia, that was channelized and lined with concrete to form a flume in the 1950’s in response to repeated flooding of the City. The concrete works negatively impacted native fish species, including rainbow trout (Oncorhynchus mykiss), and kokanee and sockeye salmon (Oncorhynchus nerka). In 2018 City Council approved a plan to restore the creek in several phases over many years. Between 2019 and 2023, Stantec prepared the design and supported the construction for the restoration of 300 m of the creek to create fish habitat and maintain flood protection. Resiliency to the 200-year instantaneous flood event (including climate change) was improved through the project with no net rise in flood levels. Climate change impacts on peak flows and groundwater impacts were considered. Analysis included 1- and 2-dimensional modelling, application of natural channel design principles, analysis of spawning gravel and flood resilience. The design involved demolition and removal of existing concrete, removal of a bridge, and re-grading the channel to create a rehabilitated riffle-pool channel with 10 riffles and 11 pools over 300 m. Aquatic habitat was improved within the reach, with a 270% increase in pool habitat that include 0.6 m deep pools that are capable of preventing loss of spawning gravels up to and including the 2-year flood event. Riparian vegetation is designed to provide cover to the channel when mature. Engagement and consultation with the Penticton Creek Restoration Committee led to a successful design, with our team meeting with this committee numerous times to share design ideas and receive feedback. This committee included City staff, and members of the Okanagan Nation Alliance, Penticton Indian Band, local fly-fishing community, and general community residents who live near the project. Construction of the downstream 200 m of the works was completed in summer 2022 with the remaining 100 m completed in summer 2023. Fish were already seen in the creek utilizing the newly constructed spawning pools in the fall of 2023.
About Leif Burge, PhD, PAg
James is a professional river engineer with 12 years of experience in the consulting industry delivering river engineering and water resources projects throughout western Canada. His expertise is in identifying and incorporating the natural tendencies of the river to provide environmentally sensitive and flood resilient solutions to his clients.
He is experienced in both the assessment of riverine processes and the design of river engineering works. His assessment experience includes: flood hazard studies, geomorphological assessments, 1-dimensional and 2-dimensional hydraulic models, erosion risk assessments, scour analyses and the analysis of infrastructure flood resiliency.
His design experience includes: flood protection measures for infrastructure, natural channel design, fish habitat restoration, water intakes, erosion protection measures, bioengineering design, watercourse crossings, bridge and culvert planning, abutment erosion protection, water monitoring stations and river accesses.
He is actively involved in all phases of projects including analysis, design development, regulatory applications, tendering, construction administration and post construction services. His career goal is to solve client’s problems by creating resilient designs that enhance the natural environment.