Australia is the driest continent on the planet, and in many regional areas, mains water supply is not available or may be restricted. Rainwater tanks serve as excellent alternative water supply, and with water costs rising, it's no surprise that, according to the Australian Bureau of Statistics, 34% of Australian households now have a rainwater tank installed. 

However, rainwater tanks also pose a health risk when not properly maintained—the NSW Department of Health records several cases of illness from drinking contaminated rainwater every year. To keep your rainwater supply fresh and safe to drink, follow the steps in this guide every 3-6 months.

1. Clean your gutters

According to the federal Department of Health, allowing soil and leaves to build up in your gutters can not only cause your water to become discoloured, but even expose the water to faecal matter or microbial growth. Clean out your gutters frequently, and consider installing a gutter mesh to prevent solids from entering your water supply.

2. Replace mosquito meshing

Most rainwater tank owners know that rainwater tanks need to be protected from mosquitoes to prevent breeding. However, in 2015, the CSIRO found that while 91% of rainwater tanks in their study had mosquito meshing installed, more than one in 10 meshes were in such a poor condition that they were of little effect. The Department of Health recommends replacing your meshing every six months, or more frequently in the tropical areas of northern Australia.

3. Regular inspections

In addition to monitoring your water supply for odours or discolouration on an ongoing basis, tank owners should also perform visual inspections of their tank and its surrounds every six months. Ensure there are no holes or gaps in the tank itself, and that there are no obvious access points for insects or larvae. If algal bloom (green scum) is present, ensure sunlight exposure is minimised. Check that the tank's pipework is structurally sound, and drain any pipes that are not self-draining.

4. De-sludging

Sediment builds up in rainwater tanks after every rainfall, and over time, this can cause water discolouration and even pose a health hazard. The National Water Commission recommends that tanks are de-sludged by a qualified contractor every two years. Doing so not only keeps your tank water fresh, but also maximises the life of your tank pump. This isn't a job that you can do yourself—besides being very unpleasant, there are health and safety risks associated with working inside rainwater tanks that mean such a task should only be undertaken by a professional.

Rainwater is an essential source of water for many Australians, but poor tank maintenance can pose serious health risks. By following these four simple steps, homeowners can enjoy their crisp, clear and free rainwater without worrying about getting sick.