GRANBY IS SHOWING OTHER CITIES THE WAY TO BETTER STORMWATER MANAGEMENT
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By Michelle Moore
The city of Granby Quebec is the first in the province to use a new stormwater management technique in 2013 that they hoped would improve the city's issues with flooding. Streets and basements would flood during heavy rainfall with existing storm drains unable to adequately drain the vast quantities of water.
The initiative came about after the city received funds from the Federation of Canadian Municipalities' (FCM) Green Municipal Fund (GMF). In January 2017 in Granby's city hall, Member of Parliament for Shefford Pierre Breton, and Mayor of the City of Dorval Edgar Rouleau announced funding for 26 initiatives in communities across Quebec.
A press release issued by the FCM explains that “through grants and loans, this $5.7 million investment supports innovative projects, studies and plans that will directly or indirectly reduce greenhouse gas (GHG) emissions and address climate change impacts." The city of Granby received a grant of $140 000 and a loan of $1 400 000 through the GMF to fix the sewer back up issue in the block surrounded by Saint-André East, Grove, Bellevue and Lansdowne streets.
This project saw no need to replace the existing system nor replace any pipes. Instead the city used "three stormwater management techniques: decreasing impervious pavement from 12 to 7 metres; installing a below-ground retention basin; and building a vegetated swale along the roadway." This method uses the natural vegetation to filter runoff water while reducing the risk of sewer backup and reducing the quantity of water overall.
The project has the added benefits of increasing green space and is said to be more cost effective than traditional approaches to storm management. It also enabled the city to build a new sidewalk and reduce road speeds giving an advantage to foot traffic and will extend the life-span of the municipal sewer system simply by reducing the amount of water intake.
I spoke to Engineering Coordinator for the city of Granby Benoit Carbonneau who said that since they carried out the project there has been no issue with flooding in that sector. He said "in the past we had a lot of problems with sewers backing up and overloading the capacity of the system we had in place." He explained that every year they do projects to improve the system.
Carbonneau explained that "part of the Green [Municipal] Fund is to inform other municipalities of innovative projects so if another city wants to do a project they’ll call us." He said many cities have contacted Granby for help with their own projects.
He added that they had done a presentation for Reseaux Environnement which is the largest group of environmental specialists in Quebec. Engineers from Granby also did a presentation for Congres INFRA for the Association of Municipal Engineers of Quebec.