Please have a look at the Fraser, Coquitlam and Pitt River Flood Extents Map (PDF) for areas which may be impacted by possible flooding.
The map represents the extent of flooding that could occur during a "design" flood event based on the topography of the land (assuming there are no dikes). The design flood is typically based on a 1-in-200-year flood which means there is a 0.5% chance of occurring in any one year. However, the design flood for the Fraser River is based on river discharges from a major flood that occurred in 1894.
The flood plain mapping extents also includes an allowance for sea level rise.