Key elements of defensible space land use bylaw provisions in wildland-urban interface municipalities of Alberta, Canada

Abstract

The province of Alberta, Canada has numerous municipalities partially or entirely within the wildland-urban interface, with anthropogenic and climactic factors increasing the level of susceptibility to wildland fires over the past century. Traditional fuel mitigation measures largely rely on landscape scale fuel management measures where treatments are often far removed from the buildings they are seeking to protect. Defensible space provisions within a municipality's land use bylaw can directly target vegetation treatments surrounding the buildings intended to be protected, and can be used alone or in conjunction with traditional landscape scale fuel management. This study investigates the use of defensible space land use bylaw provisions for increasing municipal resilience against wildland fires. The land use bylaws of 54 Alberta municipalities were examined for their inclusion of defensible space provisions. Despite a significant threat from wildland fires, many municipalities in Alberta were found to not have a defensible space provision within their land use bylaw. Key elements found to influence the strength of defensible space provisions include the operative word used, applicable structures/properties, and level of provision details. Rural municipalities were found to be more likely to have defensible space provisions, however they were generally weaker than those of urban municipalities.