2024 Track 1 Day 1: Chambers


What Line is it Anyway? Considerations for Climate Change and Stormwater Infrastructure in Floodplain Mapping


Many municipalities and conservation authorities are in the process of updating Regulatory Floodplain limits within their watersheds. However, there have not been updates to Ontario floodplain hydrology guidelines since 2002.

SWM requirements and technology has evolved significantly since this time, specifically as it relates to climate change and constructed SWM infrastructure.

Despite progress in the governance and practices of SWM, in many jurisdictions, the exclusion of stormwater infrastructure attenuation has been used as a conservative approach when delineating Regulatory Floodplain limits. In addition, there is little guidance on how to consider climate change.

This presentation will use case studies in London, ON to explore how flood limits change depending on consideration of flood attenuation for SWM facilities and climate change assumptions. A case will be made to support the inclusion of SWM ponds as part of floodplain mapping and options for climate change assumptions will be presented.


Shawna Chambers

Shawna Chambers, City of London

Shawna Chambers, P.Eng., DPA is the Division Manager of Stormwater Engineering at the City of London. Ms. Chambers holds a bachelor’s degree in Civil Engineering from the University of Waterloo – Water Resources and Environmental Engineering. and a Diploma of Public Administration from Western University.

Her 16-year career at the City has focused on the planning and implementation of municipal stormwater and wastewater projects, including leading multiple Master Plans and construction projects. As Division Manager, she focuses on delivering practical and effective stormwater infrastructure programs to benefit both the natural environment and the greater community.

Ms. Chambers is committed to sustainability, innovation, and challenging the way “it’s always been done.”