Plan & Build 

FLOODPLAIN MAPPING INTERPRETATION

The “simplified floodplain mapping” layer has combined the mapped components of the floodplain bylaw to produce a simplified version.   The “simplified floodplain mapping” layer compiles information into one area (polygon) that displays what you need to know about the floodplain bylaw for that location.  It only covers the areas where mapping was recently updated.  Previous mapping is still available using the Floodplain Mapping under the Hazards layer.

If you click through the information in the property pop-up, you will see the “simplified floodplain mapping” layer information (see example below).

Floodplain Mapping Interpretation

Under Description in the property pop-up, there are four descriptions:
Property Popup Descriptions

Restricted Area

This area is “Restricted Area” because it is either within a watercourse, like a river or lake, or it is within an area with high risk of erosion. 

When making plans for where to build a building or structure, these areas are to be avoided.

Note: You will not see further information such as FCL or alluvial fan report requirements if in the “Restricted Area” since buildings or structures are not allowed.

 

Build Above FCL, Alluvial Fan Report Required

This area is described as “Build Above FCL, Alluvial Fan Report Required” because it has been mapped as within the floodplain but risk related to flooding can be minimized by elevating habitable floor area above a defined elevation.  It is also within a rated alluvial fan, which requires further assessment to determine if proposed development is safe.

It has been mapped as an area within an alluvial fan rated “very high” or “high” risk.  An alluvial fan report is required for buildings and structures (with few exceptions as per the bylaw). 

This pop-up will include the minimum flood construction level (FCL) specified by the floodplain bylaw.  This is the elevation that all habitable space must be above.

There are also setbacks noted in this pop-up but the setbacks are not mapped.  Setbacks from natural boundaries are still applicable and must be adhered to when building. 

 Build Above FCL and Report

 

Build above FCL

This area is described as “Build above FCL” because it is within a mapped floodplain but risk can be minimized by elevating habitable floor area above a defined elevation.

Setbacks are also noted in this pop-up but the setbacks are not mapped.  The generic setbacks which are watercourse specific are still applicable and must be adhered to when building. 

 Build Above FCL

 

Alluvial Fan Report Required

This area is described as “Alluvial Fan Report Required” because it has been mapped as outside of the floodplain and free of any mapped watercourse or associated fluvial hazard but is mapped as an area within an alluvial fan rated “very high” or “high” risk. 

An alluvial fan report is required for buildings and structures (with few exceptions as per the bylaw). 

There are also setbacks noted in this pop-up but these are not related to the alluvial fan report.  Setbacks (and FCL) are only applicable if there is a watercourse nearby.

 Alluvial Fan Report required