Burlington’s Flood Reduction Study

Preparing for Extreme Weather

 

NRU
Sept. 24, 2014
By Leah Wong


In early August Burlington was hit by a heavy storm, with around 190mm of rain falling over eight hours. The rainfall resulted in more than 3,000 homes flooding. The city is using this experience to prepare for increased incidents of extreme weather.

While the Burlington Community Foundation is leading the community effort to help those impacted by the flooding the city is looking at how to better deal with future weather events.

There are three areas of jurisdiction that are responsible for flooding issues said capital works director Allan Magi. The sanitary sewer system is controlled by Halton Region; the city and Conservation Halton are responsible for surface flooding issues and private homeowners deal with issues at a lot level.

Prior to the August 4th storm Halton Region had been studying infiltration and inflow in an attempt to deal with basement flooding. The region has been upgrading its infrastructure and providing a one-time subsidy to homeowners, who have previously experienced basement flooding, to install backwater valves.

One of the challenges the city faces is the age of houses and the corresponding infrastructure. Much of the flooding was concentrated south of the QEW in the older part of the city, which was built in the pre-climate change era. There are a number of issues related to the construction of older homes, in part because design standards in the past based on smaller storms.

“One of the things [the consultants] are looking at is to review what alternatives are available to us to enhance flood protection in those areas,” said Magi. This may include upstream opportunities for flood control such as stormwater management ponds.

Both the city and the region will be working with local homeowners to educate the public on flood prevention. Older homes typically have weeping tiles that are connected to the sanitary sewers, which in extreme weather events can cause the system to become overloaded. There are many relatively minor actions local homeowners can take to prevent flooding, such as covering window wells or installing a backwater valve.

“These things are individually relatively small, but they can make a significant difference when protecting from surface water flow or stormwater getting into the house,” said Magi.

This isn’t the first time homes have flooded in Burlington, but previous storms have caused more localized flooding. Past responses have also been localized, with upgrades made based on these previous experiences, including improving the design of inlets and adding stormwater ponds. As a result the city has improved the design of its inlets and added stormwater ponds.

Though the scale of the August 4 storm was unprecedented for Burlington, extreme weather events are now occurring more regularly. Burlington, like other municipalities, is working to prepare its infrastructure and residents for future extreme events.

Burlington has hired AMEC Engineering principal consultant Ron Scheckenberger, an expert in engineering and stormwater, to analyze the storm and how it impacted the city’s stormwater system.

The first results of the study are expected to go to Development and Infrastructure Committee in the first quarter of 2015. The initial findings may identify areas of the city that need to be studied further.