Flood hazard mapping delineates flood hazard areas along streams and lakes using design flood levels established as part of flood hazard studies. Flood hazards have not been identified in all communities and may exist in areas without flood hazard studies or mapping.

Flood Hazard Mapping for Alberta Communities

GIS technology is used to display the flood hazard maps. A high speed internet connection is required in addition to following minimum computer specifications:

  • Internet Explorer 9 or higher, Safari 3 or higher, Microsoft Edge, Firefox, Chrome, as well as mobile platforms*
  • JavaScript must be enabled in your browser settings

*Although best effort has been made to make this mapping application work across all platforms, there is no guarantee of compatibility.

Flood Hazard Mapping GIS Data

The flood hazard mapping displayed in the Flood Hazard Map Application is available to the public as a digital GIS data archive. The archive was last revised on June 22, 2015, and includes five GIS shapefiles that together comprise the Alberta digital flood hazard mapping dataset.

Detailed metadata for this product may be viewed on GeoDiscover Alberta.

Flood Hazard Area Diagrams

Terminology and Definitions

Design Flood - The current design standard in Alberta is the one per cent flood, defined as a flood whose magnitude has a one per cent chance of being equalled or exceeded in any year. Although it can be referred to as a 100-year flood, this does not mean that it will only occur once every hundred years.

Design Flood Levels - Modelled water elevations within a flood hazard area based on design flood (one per cent flood event). Design flood levels do not change as a result of development or obstruction of flows within the flood fringe.

Encroachment Conditions - The flood hazard design case that assumes a scenario where the flood fringe is fully developed.

Flood Fringe - The portion of the flood hazard area outside of the floodway. Water in the flood fringe is generally shallower and flows more slowly than in the floodway. New development in the flood fringe may be permitted in some communities and should be flood-proofed.

Flood Hazard Area - The flood hazard area is typically divided into floodway and flood fringe zones and may also include areas of overland flow.

Floodway - The portion of the flood hazard area where flows are deepest, fastest and most destructive. The floodway typically includes the main channel of a stream and a portion of the adjacent overbank area. New development is discouraged in the floodway.

Overland Flow (Flood Fringe) - Areas of overland flow are part of the flood hazard area outside of the floodway, and are typically considered special areas of the flood fringe.

For more information about flood hazard mapping, contact: