Dike Breach Maps
Dike breaches were simulated as part of the Lower Fraser River 2D flood modelling project for the Lower Mainland Flood Management Strategy to develop an understanding of potential flood extents, flood progression, depths and hazard.
The simulations show how severe a flood scenario can be, how quickly it can occur, and why it is important to evacuate early, before a potential dike breach. For emergency planners, it is helpful to see the timing and extent of flooding, water velocity, and flow direction and progression when developing emergency plans. The simulations show that flooding from a dike breach can progress quickly, cutting off evacuation routes and reaching residents, livestock and/or infrastructure within a few hours.
The dike breach locations were selected to provide a range of results, not necessarily because they are more likely to breach. The locations were selected based on criteria including: the breach is capable of being modelled and may create significant local or regional impacts. The breaches are hypothetical and modelled for learning purposes only. Please refer to the notes on each map for more information.
For the following maps, the flood scenario modelled is the 1894 freshet flood event, unless otherwise stated.
- Vedder Canal [Map PDF]
- Upstream Kent [Map PDF]
- Upstream Chilliwack [Map PDF]
- Upstream Pitt Meadows [Map PDF]
- Queensborough [Map PDF]
- Upstream Delta (0.2% AEP freshet flood with 1m sea-level rise) [Map PDF]
- Chilliwack and Vedder Canal [Map PDF]
- Kent, Chilliwack, Vedder, and Matsqui (0.5% AEP freshet flood) [Map PDF]