Calgary Rivers Morphology and Fish Habitat Study

Calgary is home to five streams: Bow River, Elbow River, Fish Creek, Nose Creek, and West Nose Creek. These streams constitute valuable assets to the community and the environment. The streams provide fish and wildlife habitat, municipal water supply, recreational opportunities, aesthetic value, flood conveyance, and stormwater and wastewater conveyance routes. However, the streams also create hazards, such as flooding, erosion, and slope instability. In 2014, the City of Calgary commissioned KCB to conduct a morphology and fish habitat study to improve its understanding and management of these watercourses.

The overall objective of this project was to understand how Calgary’s rivers and creeks and the associated aquatic habitat adapt to various factors, such as urban development, flood events (particularly the 2013 flood), regulation at upstream dams, stormwater and wastewater releases, and bank protection works.

Challenges

  • Risks of erosion, flooding damage and slope instability
  • Impractical to provide room for the river, restoring the forms and dynamics of the channels of the study streams to their natural conditions because of the high value of adjacent properties and infrastructure that occupy the overbank areas.

Solutions

  • The study identified several specific actions that could be taken to reduce the risks, while restoring some of the beneficial river functions that had been damaged or lost.
  • Study sought to identify which stream interventions are essential to protecting key infrastructure, what steps can be taken to reduce/eliminate undesirable impacts associated with hydraulic structures or engineering activities, and how to improve the streams’ natural functions.
  • Interventions were evaluated and prioritized considering economic, environmental, and social factors in a Triple Bottom Line analysis. Interventions included lowering gravel bars and conducting associated fish habitat enhancement and other works.

Successes

  • The study also aimed to inform river managers and city planners over the long term by exploring future options for managing these streams to increase the city’s resilience to floods and droughts and maximize the benefits provided by these streams.