The approach for flood hazard mapping was updated to incorporating technical changes implemented in 2021 regarding how floodways are mapped in Alberta. The studies requiring updating included the Peace River Hazard Study, the Upper Bow River Hazard Study, the Medicine Hat River Hazard Study, the North Saskatchewan River Hazard Study, the Drumheller River Hazard Study, the Fort Macleod Flood Hazard Study, the Fort Vermilion Flood Hazard Study, the Camrose Flood Hazard Study, and the Whitecourt Flood Hazard Study.

NHC was contracted to update the flood hazard mapping using the new approach. The most significant changes to the flood hazard mapping approach considered in this study are:

  • Encroachment analysis will no longer be used to define floodway limits or
  • determine 1:100 design flood levels
  • Existing floodways from previous flood studies will not typically get larger when
  • flood hazard maps are updated.
  • Areas with deeper and faster moving water outside the floodway will be
  • identified within the flood fringe.
  • The protection provided by dedicated flood berms will be reflected in new flood
  • hazard maps.
  • Flood hazard maps will show areas at risk of more severe flooding.