Flood Consequence Maps
Flood Hazard Maps
Flood hazard is dynamic, and changes over time (see Flood Risk and Resilience 101). Flood hazard maps for areas within the City boundary have been developed, based on previous work completed for the CVRD Coastal Flood Mapping Project. These maps show where the flood waters are likely to go, and what depth the water is likely to reach, for three different scenarios, the following maps are best viewed on a computer:
- Present-day – Likely Event [PDF - 11 MB] (0 m sea level rise/ 5% annual exceedance probability)
- Mid-term Future – Less Likely Event [PDF - 11 MB] (1 m sea level rise/15% increase in riverine flows)
- Long-term Future – Rare Event [PDF - 8 MB] (2 m sea level rise/30% increase in riverine flows)
When it comes to understanding the potential impacts of flood events, the depth of flooding matters. With minor flooding (< 10 cm depth), most buildings are likely to stay dry, although basements may be flooded. In contrast, in more severe flooding (> 50 cm depth), water may enter the ground floors of buildings. Depth levels are indicated using colour ranges on the flood hazard maps, and reflect the different impacts to building and infrastructure that flooding may have.
These maps are a helpful guide to support a general understanding of hazard and risk. But they also have a degree of uncertainty associated with them due to factors such as data availability and modelling constraints and assumptions, and are NOT to be relied on for engineering design or regulatory controls. Please refer to the map notes, as well as to the CVRD Coastal Flood Mapping Report for further information on limitations.
Flood Consequence Maps
In addition to understanding location and depth of floodwater, it is important to understand what may be affected by floodwaters. The City of Courtenay has created Flood Consequence Maps that highlight impacts to people, buildings, critical infrastructure and disruption, cultural sites, and sensitive ecosystems.
A set of flood consequence maps were created for two scenarios: a Present-day – Likely event [PDF - 71 MB], and a more extreme Mid-term Future – Less Likely event [PDF - 62 MB]. You can compare these map sets to see the anticipated impacts for a relatively small flood event today, and a more severe event in the future with consideration of climate change.
- Consequences shown on these maps are estimates only. They are intended to support a general understanding of hazard and risk and are NOT to be relied on for engineering design or regulatory controls.
- These maps are meant to be used for illustrative purposes only. Please refer to the map notes for further information on limitations.
- The underlying hazard data contains uncertainty due to data availability and modelling; and mapping constraints and assumptions.