by Sharon Oosthoek

Climate change, coupled with burgeoning urban populations, has prompted several Ontario municipalities to consider installing harvesting systems for rainwater, which will then be used in toilets, dishwashers and watering gardens in both government buildings and residences.

Waterloo, Guelph, Durham and Toronto have all been in contact with Khosrow Farahbakhsh, an engineering professor at the University of Guelph, since he created a rooftop system that can be installed in almost any building.

“In Australia, you can buy what you need for rainwater harvesting at the equivalent of a Canadian Tire,” says Farahbakhsh, an arrangement he would like to see here. The engineer points out that harvesting rainwater need not be complicated and that many such systems exist. “Unfortunately, in Canada we don’t have many suppliers.”

Reid’s Heritage Homes in Guelph built Farahbakhsh’s rainwater system into one of its model homes, which, along with seven other buildings in the city, is part of Farahbakhsh’s research project to evaluate the effectiveness of his system. He hopes to figure out how to make the environmentally friendly practice economical and more widely accepted. Farahbakhsh would eventually like to see such systems become standard in all homes.

In a modern twist on the old-fashioned rain barrel, Farahbakhsh designed a pipe that collects rainwater from an eavestrough running along the roof. The water is filtered to remove debris and stored in a 10,000-litre tank that can either be buried in the backyard or sit above ground. Water is pumped from the tank into the house as needed.

In Farahbakhsh’s own home, the system allowed him to reduce the amount of city-supplied water he used by about 50 percent, and he notes that the set-up is ideal for industry and schools. “Seventy percent of water demand in a primary school goes to flushing toilets,” says Farahbakhsh, pointing out the wasted energy in making such water potable.