As a part of a new generation of Provincial River Hazard Studies, Alberta Environment and Parks retained NHC to conduct a flood hazard study along the Red Deer River through Drumheller and surrounding areas. The reach consists of 56 km of the Red Deer River, as well as portions of Kneehills Creek, Michichi Creek, Rosebud River, and Willow Creek.

The objective of the river hazard study is to identify and quantify river hazards along the study reach. This was done in eight major project components: survey and base data collection; open water hydrology assessment; hydraulic model creation and calibration; open water flood inundation map production; open water flood hazard identification; governing flood hazard map production; flood risk assessment and inventory; and channel stability investigation.

Between July and September 2018, 444 channel cross sections and 35 hydraulic structures were surveyed to provide detailed terrain data in support of the analysis and mapping. NHC performed an open water hydrology assessment to estimate flood frequencies of both naturalized and regulated conditions for a range of return periods at nine locations within the project reach. A one-dimensional numerical hydraulic model was developed and calibrated to support inundation and flood hazard mapping. A flood risk assessment and inventory were prepared to compute flood risk statistics for land parcels, buildings, infrastructure, and at-risk populations. Finally, a channel stability investigation was performed to provide qualitative insight about the general channel stability within the study reach. NHC’s work will help the Province of Alberta to enhance public safety and reduce potential future flood damages by identifying and quantifying river flood hazards.