Step lines define the regulatory flood elevation levels within the floodway/flood fringe. The official designated flood elevation indicated by the text applies within the section of the river between the two lines (one upstream and one downstream) where the number is written. An annotation file with the elevations is provided separately as an attachment: (Bylaw Flood Hazard Annotations).
These flood elevations reference Calgary’s Regulatory Flood Map (available separately). The Regulatory Flood Map shows the floodway, flood fringe and overland flood zones. The map is used for land planning purposes, showing the designated flood zones where various development and building regulations apply. The map shows the regulatory flood zones for the Bow River, Elbow River, Nose Creek and West Nose Creek.

For more on the development and building regulations that apply in each designated flood zone, please refer to Calgary’s Land Use Bylaw, Part 3 Division 3. http://www.calgary.ca/PDA/pd/Pages/Calgary-Land-Use-bylaw-1P2007/Calgary-Land-Use-Bylaw-1P2007.aspx

Are you building or renovating?
If you are building or renovating, check the regulatory flood map on this page, and the 1:100 year inundation map (from Flooding in Calgary: Maps http://www.calgary.ca/UEP/Water/Pages/Flood-Info/Calgary-flood-maps/Flood-maps.aspx) to see if your property is in a flood risk zone. Since late 2011, property owners have been advised of both the official designated flood elevation per the Land Use Bylaw (based on this regulatory flood map) and the most up to date recommended flood elevation (based on the updated 1:100 year inundation map) for their specific property.

Calgary’s Regulatory Flood Map shows the floodway, flood fringe and overland flood zones. The map is used for land planning purposes, showing the designated flood zones where various development and building regulations apply. The map shows the regulatory flood zones for the Bow River, Elbow River, Nose Creek and West Nose Creek. An annotation file is provided separately as an attachment: (Bylaw Flood Hazard Annotations). This map is the 1:100 flood extent calculated in 1983.

Designated flood elevations (or steplines) associated with these zones are available separately.

For more on the development and building regulations that apply in each designated flood zone, please refer to Calgary’s Land Use Bylaw, Part 3 Division 3. http://www.calgary.ca/PDA/pd/Pages/Calgary-Land-Use-bylaw-1P2007/Calgary-Land-Use-Bylaw-1P2007.aspx

Are you building or renovating?
If you are building or renovating, check the regulatory flood map on this page, and the 1:100 year inundation map (from Flooding in Calgary: Maps http://www.calgary.ca/UEP/Water/Pages/Flood-Info/Calgary-flood-maps/Flood-maps.aspx) to see if your property is in a flood risk zone. Since late 2011, property owners have been advised of both the official designated flood elevation per the Land Use Bylaw (based on this regulatory flood map) and the most up to date recommended flood elevation (based on the updated 1:100 year inundation map) for their specific property.
For Calgary's River Flood story, see: https://maps.calgary.ca/RiverFlooding/