From green roofs in Toronto to Vancouver's rain city strategy, Canadian cities are looking to become ``sponges'' in order to help mitigate some of the effects of extreme rainfall events.
In Montreal, Mayor Valerie Plante announced last week that the city plans to develop some 30 additional ``sponge parks'' designed to catch and absorb rainwater and keep it from flowing into overburdened sewers during extreme rain events.
Those, combined with an additional 400 ``sponge sidewalks,'' featuring added vegetation squares, will help the city retain the equivalent of three Olympic swimming pools in water at ``half the cost of underground works,'' the city said in a news release.
The goal is to reverse some of the harm done by the last 40 to 50 years of car-oriented urban development, which involved replacing natural spaces that soak up water with impermeable infrastructure such as roads and parking lots.
In place of absorption, water was redirected to underground sewer systems, which can become overwhelmed by heavy rain, causing flooding and contamination of rivers.