Lower Mainland emergency planning floodplain maps

The risk of catastrophic loss from flood is greatest in in the Lower Mainland because of a large population and significant infrastructure built in the floodplain area. For the purposes of flood emergency planning, the B.C. Government has provided floodplain maps showing dikes and other flood protection structures on the extent of the Fraser River floodplain.

The emergency planning maps for the Lower Fraser River have been updated (2011) to reflect minor changes to the diking system since 2009. The Fraser River flood profile and freeboard remains unchanged.

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.

Lower Mainland flood maps

The maps are not of sufficient quality to be used by local governments to designate floodplain areas.


Floodplain boundaries and supporting flood protection data are provided to support broad-based floodplain management reviews and land use planning only and not intended to replace floodplain mapping created or boundaries designated by local government or the detailed floodplain mapping created under the 1987 Canada–B.C. Floodplain Mapping Agreement (if no newer mapping has been created by the local government). Flooding may still occur outside of these floodplain areas.

The B.C. Government accepts no responsibility for the accuracy or content of the data shown on these maps. All data is subject to change and cannot be used for legal descriptions. The most current digital files may or may not be posted.