Floodplain Maps

The outcome of Part 1 of the Flood Management Plan process is updated floodplain mapping. The maps demonstrate flood conditions under a major flood event on the Chemainus River combined with a significant coastal flooding event. Two types of maps have been created:

Flood Depth & Velocity Hazard Maps (1 large map or 5 maps)
These maps show a combination of flood depth (how deep waters get in different areas) and flood velocity (how fast the water is moving) during a major flood event. This information helps illustrate the impacts of the flood event, which can support community understanding and emergency preparedness.
- Flood Hazard Map - Entire Floodplain (85MB) - this map shows the entire floodplain but can be slow to download due to size. If it is too large, the maps below divide the floodplain into four areas and are smaller to download.
- Flood Hazard Map - Index Sheet
- Flood Hazard Map - Sheet 1
- Flood Hazard Map - Sheet 2
- Flood Hazard Map - Sheet 3
- Flood Hazard Map - Sheet 4
Designated Floodplain Maps (5 maps)
These maps show the full extents of the floodplain along with Flood Construction Levels (FCLs). FCLs indicate the minimum elevation that new inhabited buildings should be built at within the floodplain (how high they need to be). This information is used in regulatory planning for land use and new development.

How to use the maps:

Both types of maps provide important information about the floodplain. The Flood Hazard Maps are often of more interest to community members.
Start with the Index Sheet of the maps you'd like to view for an overview of the floodplain and to read the notes that explain the maps.
Based on the Index Sheet, select the map for the area you are most interested in viewing (Sheets 1 - 4) and open that map.
Use the legend to interpret the flood event outputs in your area of interest. You can zoom in and pan around the map.