Rainwater Systems - Old Ways Reinvented

Boil water advisories, rising water costs, declining lake levels, incidents of Blue Green Algae, Zebra Mussels, E-Coli and Coliform, adverse well water quality and dry wells have become regular occurrences on Manitoulin Island and throughout the province of Ontario. Rainwater Harvesting provides a viable, cost saving and environmentally sound alternative for water usage.

In years past and in many parts of the world today, rainwater is the primary source of water for residential and commercial uses. Water shortages and increasing demands for water have put a focus back on using a water source that was commonly used before the advancements in drilling and treatment technologies. Rainwater can be used for nearly any purpose that requires water including in-home use, landscaping, stormwater control, wildlife and livestock watering and fire protection. 

The complexity of a rainwater system varies greatly but all systems have the same components. These are a catchment surface (roof), conveyance system (piping/eaves trough), storage (rain barrel/holding tank), distribution (pumping system/gravity) and treatment (purification equipment). Water used for drinking water must be treated to an acceptable level.

The use of rainwater can be throughout the entire house, wash the car, flush your toilet or water the garden. Unwanted water can be kept from collecting around your property causing damage. A common system would be a storage tank fed from a roof and treated for the required usage ie: drinking water or grey water. It can also be a rainwater barrel in the backyard or troughs for watering livestock. Larger systems can provide water to commercial buildings. A good example of this is the installed 22,000 gallon system at McMaster University in conjunction with UV Pure Technologies to reduce the overall water operating costs and dependency on municipal water by providing water to fountains, a coffee shop and toilets. The applications for rainwater are endless and gaining popularity in Canada for water conservation and cost savings measures.

Well owners who have experienced wells going dry and hauling water could significantly benefit from a supplemental rainwater system. This would also apply to areas with no access to water or low yielding wells. In addition, it is highly oxidized and an excellent source for gardens and vegetable growth. Naturally soft, there are no problems with scaling, odour or staining commonly found in deep well and shore well applications. Municipal water users would have the long term savings of reduced water bills and chlorine free water. Water filters would not need frequent changing because the water line has receded and the foot valve is in less than two feet of water drawing from the lake bottom.

Consider the potential volume of water during a rainfall. One square meter of roof surface can produce 1 litre during a 1 mm rainfall.  The average roof measuring 140m2 or 1500 ft2 can generate 935 gallons during a 1 inch rainfall.  The average precipitation for Manitoulin Island is between 31 and 35 inches of per year. This would mean that an average home could expect around 29,000 to 33,000 gallons of water per year. Obviously some of this will not be available during the winter months but realistically an 8 to 9 month season available for rainwater usage.

While far from being a new idea this is a concept that has many advantages, creating solutions to problems and advancements in treatment technologies provide a safe water source for wide variety of uses.