Manning Flood Study: Update
The Manning Flood Study will assess and identify flood hazards along 24 km of the Notikewin River through Manning and County of Northern Lights.
Hydraulic modelling, flood inundation mapping, and flood hazard mapping along the Notikewin River are the primary deliverables of the new study, but the study also includes foundational survey and base data collection and hydrology assessment components.
The study began in spring 2023 and technical work is expected to be complete by spring 2024. River survey work is finished and other base data collection is underway. Hydrology assessment is in late stages and work on other components is in early stages. The focus of our consultant over the next months will shift to hydraulic modelling and flood mapping.
We recognize there will be tremendous interest in any new flood mapping. Our study finalization process includes municipal review and public engagement for major components, as appropriate. Our goal is to provide useful tools to communities and the public as soon as possible.
The study is being completed under the provincial Flood Hazard Identification Program, the goals of which include enhancement of public safety and reduction of future flood damages through the identification of river and flood hazards. The provincial study is being co-funded through the federal Flood Hazard Identification and Mapping Program.
Project background and study progress
The Manning Flood Study will assess and identify flood hazards along 24 km of the Notikewin River through Manning and County of Northern Lights.
The main study components outlined below include new hydraulic modelling and flood mapping, but all deliverables support local emergency response and land-use planning needs.
- Survey and base data collection – Late stages
Hydraulic models and flood maps require high-accuracy base data. Field surveys and LiDAR remote sensing are used to collect river and floodplain elevations, channel cross section data, bridge and culvert information, and dedicated flood control structure details.
- Hydrology assessment – Late stages
The hydrology assessment estimates flows for a wide range of possible floods along the Notikewin River, including the 1:2, 1:5, 1:10, 1:20, 1:35, 1:50, 1:75, 1:100, 1:200, 1:350, 1:500, 1:750, and 1:1000 floods.
- Hydraulic river modelling – Early stages
A new hydraulic computer model of the river system will be created using new survey data and modern tools. The model will be calibrated using surveyed highwater marks from past floods to ensure that results for different floods are reasonable.
- Flood inundation mapping – Early stages
Flood maps for thirteen different sized floods, based on the hydraulic model results and the hydrology assessment, will be produced. Flood inundation maps can be used for emergency response planning and to inform local infrastructure design. These maps identify areas of direct flooding and areas that could be flooded if local berms fail.
- Flood hazard mapping – Early stages
Flood hazard mapping divides the 1:100 floodplain into floodway and flood fringe zones, to identify where flooding is deepest and most destructive. These maps can be used to help guide long-term development planning.
More information about the Alberta Flood Hazard Identification Program can be found at: www.floodhazard.alberta.ca
If you have any questions regarding this work, we can be contacted at: aep.flood@gov.ab.ca
Updated July 19 2023