Roofwater is a high quality water source suitable for most end uses with minimal treatment. Treatment usually starts upstream of storage with screening and first flush devices employed to prevent debris and initial dirtied runoff from entering the harvesting system. After storage, roofwater is typically filtered using a simple micro strainer. Disinfection may also be required for end uses such as irrigation and washing where there is potential for human exposure.
Most roofs are suitable for roofwater harvesting and the natural elevation assists in keeping systems above ground to minimise pumping requirements.
The control requirements of a roofwater harvesting system vary with the complexity of the system. A small control panel for the distribution pumps is often sufficient to operate the entire system and track water savings. If available, a mains water connection may be used to top-up or back-up supply.
Key engineering considerations for roofwater harvesting systems are summarised further below and in the attached brochure.
Key considerations:Exposure of roof areas to contaminants Roofwater diversion point and mechanism
Key considerations:Storage tank location, capacity and material Need for pre-screening and first flush devices Level of filtration and disinfection needed to meet end use requirements
Key considerations:Delivery pump type and activation mechanism Need for and location of mains water top-up or back-up
Key considerations:Control capability and required level of system automation Type and number of sensors and control hardware