Description: Alberta Flood Hazard Mapping GIS Data Archive - AB_FHM_FLOODWAY_20130809.ZIP IMPORTANT! This digital data may not reflect official flood hazard areas delineated in original hardcopy mapping produced under the Flood Hazard Identification Program. Contact the River Forecast Section for clarification if the precise flood hazard extent or a design flood level is critical to any application. This digital data archive is updated when new information is available or existing information changes, and the currency of its flood hazard mapping assets are not guaranteed. Refer to the Supplemental Information section of this document for important information regarding data and conversion processes. IMPORTANT! Alberta Environment and Sustainable Resource Development identifies flood hazard areas across the province as part the Flood Hazard Identification Program. Studies commissioned as part of the program are comprised of reports and mapping. Flood hazard mapping delineates areas that would be inundated during the 100-year design flood under encroached conditions and provides design flood levels along study cross sections. The flood hazard area is divided into floodway and flood fringe components to support appropriate flood hazard area management. The floodway area is that portion of the river channel and floodplain required to convey the 100-year design flood. The floodway is where flood flows are deepest, fastest and most destructive. New development is discouraged in the floodway and may not be permitted in some communities. The flood fringe is the area outside of the floodway that will still be flooded during the design event, and may include overland flow areas. The water in the flood fringe is generally less than one metre deep and flows more slowly. Development in the flood fringe may be permitted provided that its adequately floodproofed to accommodate design flood elevations and any required freeboard. The current design flood standard in Alberta is the 100-year flood, determined when a flood hazard study is undertaken. A 100-year flood is defined as a flood whose magnitude has a one percent chance of being equalled or exceeded in any year. The design flood can also reflect a computed 100-year water level resulting from an ice jam or be based on a historical flood event. Design flood levels are water elevations within a flood hazard area computed to result from a design flood under encroachment conditions. Encroachment conditions assume a future scenario where the flood fringe is fully developed and flood flows are conveyed entirely within the floodway. Design flood levels should not change as a result of development or obstruction of flows within the flood fringe. More information on the Flood Hazard Identification Program can be found at http://environment.alberta.ca/01260.html. The website includes synopses and background information for all official Alberta Environment and Sustainable Resource Development flood hazard studies. Official flood hazard mapping for communities across Alberta is available online using the Flood Hazard Map Application at http://www.envinfo.gov.ab.ca/FloodHazard/. The application uses GIS technology to display mapped areas, including cross section locations and design flood levels along with links to specific study pages. Flood hazards have not been identified in all communities and may exist in areas without official flood hazard mapping produced under the provincial Flood Hazard Identification Program. Contact the River Forecast Section for additional information.