Alberta Environment and Parks
Alberta Environment and Parks retained NHC in June 2021 to complete a flood hazard study for the Town of Milk River and adjacent areas in Warner County. The study area includes a 7.2 km long reach of the Milk River within Warner County, including the town of Milk River.
The study is conducted according to Flood Hazard Identification Program Guidelines, incorporating technical changes implemented in 2021 regarding how floodways are mapped in Alberta. The overall objectives of the study are to enhance public safety and to reduce potential future flood damages and disaster assistance costs.
The study is comprised of five major project components (Survey and Base Data Collection, Open Water Hydrology Assessment, Open Water Hydraulic Modelling, Open Water Flood Inundation Mapping, and Design Flood Hazard Mapping).
Frequency floods with various return periods were determined through the hydrology assessment. A hydraulic model was created with the survey data and validated to observed floods. The model was used to simulate a total of 13 flood scenarios, and flood inundation maps were subsequently created for the 2-, 5-, 10-, 20-, 35-, 50-, 75-, 100-, 200-, 350-, 500-, 750-, and 1000-year events. The results were used to delineate the floodway and flood fringe boundaries and to create floodway criteria/flood hazard maps.