Mountainous regions and valleys of British Columbia suffer from damaging floods, debris floods (a flood with very high sediment transport) and debris flows (a liquid landslide) that often result in property damage, sometimes in loss of life and frequently in the interruption of crucial transportation corridors.

Despite the high frequency of damaging geohazard events in BC, systematic identification and assessment of geohazard risk has not yet been completed at provincial scale. With local government partners, we are characterizing developed areas exposed to clear-water flood, debris flow and debris flood geohazards across approximately 300,000 km² of southern British Columbia. Volcanic debris flows and landslide-dam outbreak floods are also assessed in some areas.

We prioritize hazard areas using the principles of risk assessment, considering how often a damaging event can occur and what the likely damage would be. We are also completing detailed follow-up assessments that help advance a long-term vision for natural hazard risk reduction planning, implementation and monitoring in British Columbia. This work is supported by the development of Cambio, which is web-based software that supports with data organization, prioritization analysis, results communication, and on-going geohazard management. 

With over 10,000 prioritized geohazard areas and hazard susceptibility modelling completed across tens of thousands of watersheds, this work is BC’s most extensive flood and steep creek geohazards assessment to date. These study results and supporting software will support government partners tasked with long-term geohazard risk-informed development planning, bylaw enforcement, flood resiliency and emergency response planning.