Rain City: Vancouver puts new focus on rainwater management

Vancouver is notorious for its heavy rainfall, but the environmental impact of all that water is perhaps not as well known.

The City of Vancouver is addressing that general lack of rainwater knowledge during a series of public workshops starting March 3.

The workshops are part of the Rain City Strategy, which aims to limit the amount of polluted road water run-off going into the ecosystem.

"We're a city of glass, concrete, asphalt, buildings ... The rain just doesn't have a lot of places to go," said Melina Scholefield, director of green infrastructure implementation for the City of Vancouver.

The goal of the Rain City Strategy is to capture and clean 90 per cent of rainwater in the city. To that end, the city is implementing new rainwater management practices that aim to use rainwater as a resource, rather than a waste product.

The target will be achieved by using a combination of "green" infrastructure and conventional pipe systems.

Harmful particulates

"A lot of people haven't realized just how much of an impact pollutants have in our storm water system,"  said Scholefield.

Scholefield said many of Vancouver's older roads were not designed with the environment in mind. When it rains, the water run-off from streets can damage the ecology of surrounding bodies of water.

"There are lots of pollutants in the water run-off that people typically aren't aware of," said Scholefield.

When a vehicle pumps its brakes it can release copper particulates onto the road. When a car's tires start to disintegrate, zinc from the tires can end up on the street.

Those little particulates, and other types of pollutants, get picked up off the roads in the run-off, go into the sewage pipe system, and are then drained into receiving bodies of water, such as False Creek, during heavy rainfall.

"We really want to try and find a way to protect our aquatic habitat, make a healthy environment, and make sure we're cleaning the water before we release it," said Scholefield.

Scholefield said Vancouver's growing population presents an excellent opportunity to implement green practices when building new housing. 

When moving forward with housing developments, Scholefield said Vancouver's Olympic Village is an exemplary model to follow.

Two-thirds of the road run-off in the Olympic Village is cleaned using a "bio wetland."

That bio wetland is deceptively presented as a little pond frequented by wildlife, but it's actually part of a targeted rain water management system. 

By using permeable surfaces, much of the pollutant-rich rainwater in the area is allowed to absorb into the ground.

Whatever water isn't absorbed is collected through a pipe system, which drains into the wetland, where it is treated through natural systems, like plants, and cleaned of harmful elements. The newly cleaned water is then released into False Creek.

Scholefield said new housing developments should be built with "green roofs," like many of the buildings in the Olympic Village. A green roof has a garden on the top of the building that catches rainwater.

Also, much of the captured and cleaned rainwater in the Olympic Village is recycled for toilet flushing, she said.

There are almost 200 strategically placed gardens around Vancouver that help clean water in a similar way to the bio wetland, added Scholefield.

The first workshop starts at 11 a.m. Saturday and will be held at 511 West Broadway. 

With files from The Early Edition