Floodplain Management Bylaw Guide for Residential Construction

Much of the City of Chilliwack lies in the floodplain of the Fraser River to the north, the Vedder River to the south, the Sumas River to the west or one of several creeks entering the valley from hillside areas.

In order to reduce the potential damage which would occur should one or more of these rivers overtop their banks or protective dykes, the City of Chilliwack and the Province of British Columbia have developed appropriate floodproofing requirements for various forms of development.

Council has adopted the Floodplain Management Bylaw No. 3080, which regulates construction elevation requirements for new development in the floodplain.

1. HIGHLIGHTS:

  • there are no longer any areas exempt from floodproofing requirements;
  • floodproofing requirements for residential development are generally increased; and
  • a new floodplain category “Alluvial Fans” has been created.

2. RESIDENTIAL DEVELOPMENT:

  • General Floodplain Area (not special cases)
    • underside of lowest habitable floor or pad height for a mobile home must be constructed to Flood Construction Level (FCL);
    • garage, carport, entrance foyer are exempt;
    • no basement (maximum 1.5m deep crawlspace permitted subject to local drainage requirements); and
    • NO COVENANT IS REQUIRED.
  • Yarrow Area
    • same as General except as follows:
    • where the difference in elevation between the FCL and average grade is more than 2.5m, the underside of lowest habitable floor may be constructed to 1.2m above average grade; and
    • A COVENANT IS REQUIRED.
  • Greendale and other low areas:
    • same as General except as follows:
    • where the difference in elevation between the FCL and average grade is more than 2.5m, the underside of lowest habitable floor may be constructed to 2.5m above average grade; and
    • A COVENANT IS REQUIRED.
  • Farm Dwellings on parcels with the ALR exceeding 8.0 ha in area:
    • same as General except as follows:
    • lowest habitable floor may be constructed to 1.0m above average grade; and
    • A COVENANT IS REQUIRED.
  • West of Young Road (N. of Hope Slough / S. of Cartmell Rd.)
    • same elevations as General Floodplain Area; and
    • A COVENANT IS REQUIRED
  • Alluvial Fan Areas
    • Engineered concrete foundation must be constructed to 1.0 meters above grade.

Consult Floodplain Management Bylaw No. 3080 for additional details and for further information please contact:

City of Chilliwack
Development and Regulatory Services Department
Telephone:  604.793.2905
Fax:  604.793.2285
8550 Young Road
Chilliwack, BC   V2P 8A4

This brochure has been prepared to provide guidance only.  It is neither a bylaw nor a legal document.  Please consult the Local Government Act and its regulations, and the City of Chilliwack Zoning Bylaw and applicable reference for definite requirements and procedures.