Almost everyone is familiar with rain barrels, but have you heard of rain roofs?
Enter the Elmira-based environmental consulting firm Enviro-Stewards, which designed a unique roof system called blue roofs, intended to help improve stormwater management, reduce flooding risk, and improve urban resilience against climate impacts.
“What they do is hold the rainwater on their roof, and then when another rain event is coming, it gets released into the stormwater, but then there is not such a high demand on the current wastewater infrastructure,” said Tova Davidson, executive director of Sustainable Waterloo Region, adding that they are a useful tool for organizations looking for a climate mitigation tool.
“I think we are definitely seeing the changing climate and the changing weather patterns from the changing climate, and a lot of good business management practices mean that you are reducing your risk exposure for your organization,” she said.
“So, as those more severe weather events become more common, we’re seeing 100-year storms far more often than we used to, it becomes necessary just to allow business to continue to function the way it always has.”
Blue roofs are a climate adaptation tool that helps cool down a building, which also saves business owners on energy costs while reducing the impact of severe weather.
While Enviro-Stewards have been around since 2000, blue roofs are one of the company’s newer projects, implemented around five years ago.
“We first did it on our own roof here in Elmira as a kind of a test case and a pilot project. And since we’ve installed it at places like Credit Valley Conservation, and a manufacturer in Walkerton, they use it in a more industrial sense,” explained Mats van Kleef, president of Enviro-Stewards.
Blue roofs are geared more towards industrial buildings than residential ones since they only function with a flat roof. Containment barriers and automated valves store heavy rainfall on flat roofs. Then the trapped water slowly drains and cools the building through evaporation.
“We have mostly done it with businesses because they typically have a larger flat roof, and it needs to be flat because otherwise the water will just run off. And most homes have a slanted roof. Maybe the equivalent in homes would be a rain barrel, where you can do that on a smaller scale,” said van Kleef.
Enviro-Stewards has built their blue roof so that some of the water held goes towards greywater use for things such as flushing toilets.
“We have a drain pipe that comes down from one section of the roof, and that lets it into an intermediate tank. We have a tank sitting in our office that probably has two cubic metres of water in it, and we can top it up. If the water is starting to get low then we can open the valve and let more water from the roof into the tank, or if it’s full, then just keep the water up on top of the roof,” said van Kleef.
“Then from that tank that we have in the office, there’s a pump that directs it to the living wall and to the toilets through purple piping, just to make sure that it’s very clear for everybody that it’s not potable water, but it’s rainwater that gets reused.”
Beyond blue roofs, Enviro-Stewards has several other sustainability-related endeavours, many related to water conservation.
“The work that we do that is our bread and butter is helping save water in factories,” said van Kleef.
Enviro-Stewards have sensors that go into factories to track water usage minute by minute, which shows where companies are using their water and how they can save their water consumption.
“One example of a factory in Toronto was that they had continuous water still flowing even on weekends when they weren’t in production. There was nothing happening in the factory, but there was still six cubic liters per minute flowing down the drain,” said van Kleef.
The sensors looked at where water was flowing and found a couple of broken valves and sensors and a broken pipe that were the culprit.
“These were all things that the company wasn’t aware of, but when we put sensors in all these places, we could show how much water was being lost in the drain in each of those places, and just manually shut off the water supply to those processes,” said van Kleef.
For more information, visit www.enviro-stewards.com.
