Planning on developing a property near the Sheep River? There are many regulations in place that outline the requirements that need to be met in this area.
Relevant terminology and definitions from Alberta Environment and Parks and Sustainable Resource Development.
The current design standard in Alberta is the one percent flood, defined as a flood whose magnitude has a one percent chance of being equaled 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.
Modeled water elevations within a flood hazard area based on design flood (one percent flood event). Design flood levels do not change as a result of development or obstruction of flows within the 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.
The flood hazard area is typically divided into floodway and flood fringe zones and may also include areas of overland flow.
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.
The Government of Alberta has completed flood studies and mapping engagement as part of their Flood Hazard Assessment Program. This information is meant to improve public safety, support emergency management and help build safer and more resilient communities over the long term. The Sheep River Flood Study assesses and identifies flood and river-related hazards along 60 km of the Sheep River upstream of the Highwood River confluence, and 35 km of Threepoint Creek upstream of the Sheep River confluence. The study area includes Diamond Valley, Okotoks, and Foothills County, including Millarville.
Status: The study was completed between February 2017 and May 2025, and was finalized on May 15, 2025.
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.
If you require more information, please contact Planning Services at the number at the bottom of the page or submit an online inquiry: