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How to build cities that can stand the rain

With 100-year storms coming every 10 years, cities are bracing for higher water levels and filtering out the troubles that come with them.

The roof on the West building of Vancouver Convention Centre boasts one of the largest green roofs in the country. The permeable surfaces help cut down on stormwater run off.

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The roof on the West building of Vancouver Convention Centre boasts one of the largest green roofs in the country. The permeable surfaces help cut down on stormwater run off.

As climate change becomes a fact of life, natural disasters will hit cities harder and more often.

While touring areas of Quebec devastated by flooding last week, Prime Minister Justin Trudeau warned about future struggles. “We’re going to have to understand that bracing for a 100-year storm is maybe going to happen every 10 years now or every few years,” he said.

Here are some ways cities are making themselves storm resistant.

Green Roofs: Traditional hard roofs cause large amounts of runoff in cities. Many places are prioritizing “green roofs” covered in vegetation to counteract that effect. Measuring six-acres, the green roof on the West building of the Vancouver Convention Centre is one of Canada’s largest.

Constructed Wetlands: In the outskirts of Calgary, the 156-hectare man-made Shepard Wetlands functions as a storm water storage facility, treatment centre and wildlife habitat that naturally filters storm water before it enters the Bow River.

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Bioretention Parkettes: In Toronto, the Coxwell/Fairford parkette is one of the first of its kind in Canada. It uses plants to collect and treat stormwater runoff from the surrounding roadway and replaced paved-over surfaces with trees and thousands of pollinator plants.

Twitter/RyUrbanWater

Green Streets: The City of Paso Robles, Calif., wanted to reduce street flooding, so in 2014 it turned 21st Street into a “green street.” Part of the redesign included adding a median filled with plants to filter runoff and slow the flow into sewers.

Contributed/Cannon

Urban Watershed: In Seattle, Wash., the Growing Vine Street project uses a series of downspouts, and cascading planters to capture and filter rainwater to ease pressure on storm sewers. Some are even used for irrigation.

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