How Rainwater Harvesting works with Blue-Green Roofs
06/062023
Happy Green Roof Day! Did you know that Rainwater Harvesting can be used with Blue-Green Roofs to count towards onsite attenuation capacity and provide a sustainable water supply within the building? Combining the two technologies just makes sense in a world where potable water supplies are becoming threatened by unpredictable weather patterns. Not only is supply and demand an issue, but localised flood risk too. In fact, over the next 25 years summer rainfall is predicated to become 20% more intense.
Blue-Green Roofs provide newly constructed buildings with above ground attenuation capacity in the roof area where space may be limited below ground for storage. These types of roofs also have a natural cooling effect for the building too, reducing the need for energy intensive cooling systems. As well as providing a natural habitat for insects to thrive, Blue-Green Roofs are another tool in the overall SUDs package.
Combining Blue-Green Roof Systems with a Rainwater Harvesting System can further alleviate pressure on surrounding drainage infrastructure and help to reduce the likelihood of combined sewer releases into our rivers and oceans. With a combined system, storm water runoff can be captured during heavy rainfall and reused for non-potable applications. Traditionally, a rainwater harvesting storage tank would be located at the base of the building meaning the reused rainwater needs to be pumped up to points of use. By combining with a Blue-Green Roof System, the pumping requirements are dramatically reduced as water is transported via gravity, reducing energy and carbon.
How does it work?
A combined Rainwater Harvesting System and Blue-Green Roof System does not require a traditional large rainwater harvesting storage tank. Instead, water in the attenuation capacity of the roof is supplied directly into the rainwater harvesting system. A small break tank with mains water top up ensures there is always enough water available to serve the points of use, even during low rainfall.
Using Active Attenuation technology, in collaboration with our friends at Storm Harvester, the Rainwater Harvesting System communicates with the Met Office to ensure 100% of onsite attenuation capacity is always available for an incoming storm.
When a storm is detected by the Active Attenuation Technology, a valve opens to release the necessary volume of water for the incoming storm. The requirement for this valve to be operated is dramatically reduced due to the captured rainwater being reused within the building for toilet flushing, vehicle washing and irrigation.
Learn more
Speak to our friendly team of experts about the benefits of combining a Rainwater Harvesting System with a Blue-Green Roof here.
Written by Matt
Water Reuse Specialist
Water Reuse Specialist
My role as a Water Reuse Specialist means I get to keep up to date with all things water conservation. My favourite water saving tip is to turn taps off when brushing your teeth! I think rainwater harvesting and the water reuse industry is exciting, and I love sharing updates with our customers. View Matt’s Stormsaver profile here.
