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Flood maps for Calgary

Types of flood mapping

The City of Calgary offers a number of different maps that present flooding data. The two main types of detailed flood mapping are flood hazard mapping and inundation mapping described below.

For frequently asked questions related to flood mapping in Calgary, please visit our Flood Mapping FAQ page.

River flooding overview mapping

We have created overview maps which show communities that have the potential to be impacted by river flooding.

Flood hazard mapping

The flood hazard map is used for land use planning purposes. It shows where surface flooding occurs for a flooding event that has a one per cent chance of happening every year, also called a 1:100 year event.

This map was created by the Province of Alberta in 1983, with updates in 1996. It is embedded in the City of Calgary's Land Use Bylaw. The flood hazard map shows where floodway, flood fringe and overland flow zones are located. These zones represent varying levels of risk and have different development and building design rules or guidelines.

Most formats of the flood hazard mapping also show designated flood elevation or step elevations. Property owners are are provided with the designated flood elevation applicable to their property. Building design elements are regulated to this elevation.

To find out if your property is in a floodway or flood fringe area, we recommend that you visit the Province of Alberta's official Flood Hazard Map. You can also find more information at their flood hazard mapping site. The Province is currently creating updated flood mapping for Calgary, and will be producing a new flood hazard map.

Flood hazard mapping and step elevations are available in a variety of formats, showing the floodway, flood fringe and overland flow zones on the Bow and Elbow Rivers, Nose and West Nose Creeks. Please choose from the options below:

City Online interactive map
This map shows the floodway, flood fringe and overland flow zones but does not show designated flood elevations.

PDF maps
These maps show the floodway, flood fringe and overland flow zones as well as designated flood elevations. They are organized by City of Calgary excluding downtown and beltline, and downtown and beltline only.

Land Use Bylaw maps
The City's Land Use Bylaw Maps show the Land Use District for each parcel of land in the City, and can be useful when determining whether your property is in the floodway or flood fringe.

Inundation mapping

Inundation maps are created for flood reponse planning, infrastructure design and environmental purposes, based on modeling in 2015. They show the area of surface flooding for 5-year, 10-year, 50-year and 100-year return periods.

To view the inundation maps, visit inundation mapping.

The three distinct types of inundation are identified as the following:

  • Inundation
    Area flooded due to riverbank overtopping
  • Isolated
    Low lying areas that will not be wet from riverbank overtopping, but may experience groundwater seepage or stormwater backup
  • Potential failure of flood protection barrier
    Low lying areas that could be flooded if an existing permanent flood protection barrier were to fail.

In some areas, the inundation shown on these maps for the 1:100 year turn period event is different than the inundation in the flood hazard mapping.

This is because the flood hazard map was created in 1983, and since then we have collected more data which changes the statistical and hydrologic analysis, as well as the watershed and river have changed over time. In general, the 1:100 year river flow and elevations at most locations has increased from the 1983 analysis.

Since late 2011, property owners have been advised of both the official designated flood elevation per the Land Use Bylaw (based on flood hazard mapping) and the most up to date recommended designated flood elevation (based on inundation mapping) for their specific property.

Aerial photos taken during the 2013 flood

In June of 2013, the City of Calgary took highly accurate aerial photographs of the areas of our City impacted by the flood. Those photoes are available to the public for free at CityOnline.