Bats and rainwater tanks

Flying foxes (or fruit bats) often feed at night on native and introduced tree species in residential areas. These mammals carry a range of potentially harmful micro-organisms.

If flying foxes are present around your residential area and occupying locations on or above roofs, guttering or rainwater tanks, there is potential for them to contaminate the rainwater.

This could happen when contaminated material (faecal material from the animals) containing viruses, bacteria or other micro-organisms, collects on the roof and get washed into the rainwater tanks.

If managed well, rainwater tanks can continue to provide a source of water suitable for drinking or other domestic purposes.

How to reduce risks

There are several things you can do to help reduce the likelihood of your rainwater tank becoming contaminated:

• Install a first flush device to divert the initial dirty water flow away from the tank
• Use a 1mm (or less) mesh screen to prevent material from entering the tank when roof run off water is collected
• Inspect tank for bottom sediments and flush tank to remove debris if possible (every six to 12 months)
• Prune or remove all overhanging vegetation and debris from roofs, gutters or tanks (every three to six months)
• Check for evidence of animal access to tank and repair and close any openings to the tank (every six months)
• Regularly disinfect the rainwater tank by adding a suitable disinfectant (e.g. 40mL of liquid sodium hypochlorite per 1000L of water).

Maintaining safe rainwater for drinking purposes requires a small amount of maintenance to help ensure that the rainwater supply is free of contamination.