The 2019 Lower Fraser River 2D Flood Modelling and Mapping Project is a major component of the Lower Mainland Flood Management Strategy. The flood model estimated the extents and depths of flooding from a range of flood scenarios.
The Fraser River Freshet flood depth maps linked below are intended to help with regional flood planning. In particular, the maps help those with responsibilities for flood management:
Better understand current and future flood hazards
Advance work on risk assessment to help prioritize high-risk areas
Evaluate flood risk reduction options, and
Enhance emergency preparedness and response planning.
These regional flood hazard maps are based on modelling a limited number of flood scenarios and are for regional planning purposes only. These are NOT projections of whether or when future flood events may occur and are not of sufficient detail for local flood planning or analysis.
The maps in this section:
Should NOT be used for officially designating floodplains, establishing flood construction levels, or designing dikes or other structures. Government authorities require more detailed, local mapping and analysis to designate floodplains for these purposes.
Do not show flooding from other rivers, streams, and creeks in the region, except backwater effects from a Fraser River flood.
Show the maximum flood depth (highest level during the flood). Flood depths will vary by location and stage of flooding.
Are based on the Lower Fraser River 2D Flood Model unless otherwise stated.
Assume that existing dikes are present unless otherwise stated. In scenarios where the modelled flood level is higher than the dike, the maps account for dike overtopping (i.e., water rising above the height of the dike and flooding the other side). But dikes can fail in other ways, such as piping and seepage, before they are overtopped during a flood – these are not accounted for in the following maps.
Must identify the the Fraser Basin Council (on behalf of the Lower Mainland Flood Management Strategy partners) as owner of the maps.
May NOT be used commercially in any way without permission of the Fraser Basin Council
May NOT be modified in any way without permission of the Fraser Basin Council.
Lower Fraser River Freshet Flood Scenarios Maps
Note: While reduced in size for web access, the PDF map files are large and may take few moments to view in your browser or download.
Fraser River Freshet (Spring) Flood Scenarios – Present Day
The five maps below show flood depths and extents for Lower Mainland Fraser River freshet floods of increasing magnitudes based on the historical record and today’s climate (present day conditions).
1894 freshet flood event. [Map PDF] The 1894 Fraser River flood is considered to be slightly more severe than the estimated 0.2% AEP (500-year) flood today. This is considered the “design flood” to inform dike design and construction along the lower Fraser River.
Fraser River Freshet (Spring) Flood Scenarios – Year 2050 with Climate Change
The two maps below estimate flood levels under projected climate change conditions in 2050. The conditions include 0.5-metre sea level rise and changes in peak river flows. A 1% AEP (100-year) flood in 2050 will be more severe than a 1% AEP flood today. Similarly, a 0.5% AEP (500-year) flood is projected to be more severe in 2050 than today.
Year 2050 1% AEP (100-year) freshet flood with 0.5m sea level rise. [Map PDF]
Year 2050 .2% AEP (500-year) freshet flood with 0.5m sea level rise. [Map PDF]
Fraser River Freshet (Spring) Flood Scenarios – Year 2100 with Climate Change
The three maps below estimate flood levels under projected climate change conditions in 2100. The conditions include 1-metre sea level rise and changes in peak river flows. A 1% AEP (100-year) flood in 2100 will be more severe than a 1% AEP flood today.
Year 2100 1% AEP (100-year) freshet flood with 1m sea level rise. [Map PDF]
Year 2100 0.5% AEP (200-year) freshet flood with 1m sea level rise. [Map PDF]
Year 2100 0.2% AEP (500-year) freshet flood with 1m sea level rise. [Map PDF]
Higher resolution versions of the maps (large files) are available on request.
For more information about the mapping project and the maps, please contact:
Steve Litke, Senior Program Manager Lower Mainland Flood Management Strategy E:
Social well-being supported by a vibrant economy and sustained by a healthy environment.
About the Fraser Basin Council
The Fraser Basin Council (FBC) is a charitable non-profit organization that brings people together to advance sustainability in the Fraser River Basin and throughout BC. Established in 1997, FBC is a collaboration of four orders of government (federal, provincial, local and First Nations) along with those from the private sector and civil society. We work with people in multiple sectors, helping them find collaborative solutions to today’s issues through a commitment to the social, economic and environmental dimensions of sustainability. Our focus is on healthy water and watersheds, action on climate change and air quality and strong, resilient communities and regions.