Hume City Council is leading the way in saving water by harvesting rainwater for a variety of tasks, from vehicle wash down to garden irrigation and flushing public toilets.
Council has an Integrated Sustainable Water Management Plan – Corporate Action Plan, which focuses on reducing the use of reticulated drinking within Council operations, such as municipal depots, community centres, administration buildings and sporting fields.
Hume City Council’s second rainwater tank installation is at the Sunbury Works Depot, collecting rainwater from 1300sq m of roof area.
The rainwater is then stored in five polyethylene storage tanks which have a combined capacity of 114,000L.
The storage tanks are connected to the mains water supply and are combined with a Davey Water Products ’ RainBank automatic controller which switches the water supply between the mains and rainwater stored in the tanks.
Whenever sufficient rainwater is available in the storage tanks, the Davey RainBank controller will automatically draw on this source.
If insufficient water is held in store, only then will the flow be drawn from the mains supply.
Stuart Nesbitt, Hume City Council’s Sustainable Resource technical officer, says that the rainwater harvesting system at the depot is calculated to save one megalitre (one million litres) annually. Sunbury, like many parts of Australia, has a reliable average monthly rainfall of about 50mm.
“That’s enough to fill or top up our tank storage system regularly, so we anticipate being able to use our stored rainwater for a diversity of applications, from truck and equipment washing to garden irrigation,” says Nesbitt. “Our depot staff were amazed to see just how much rainwater ran off the roof after recent rainfall, and how quickly the five tanks were filled.”
Harvesting rainwater enables home owners and commercial users to conserve water by avoiding the use of drinking water supplies for what are essentially low grade water uses, such as toilet flushing, laundry use, garden irrigation or vehicle washing.
Nesbitt says the Sunbury Works Depot rainwater harvesting system is the second installed by Hume City Council.
“We have another one which has operated for some time, where collected rainwater is used as a priority over mains water for toilet flushing in one of our community buildings.” Again, a Davey RainBank automatic controller determines the priority of stored rainwater over mains water whenever there is a demand.
At both sites, a Davey RainBank automatic controller automatically selects and pressurises stored rainwater as a priority over mains supply, whenever rainwater is available.
A RainBank automatic controller can be readily incorporated in any rainwater harvesting system.