Risks to drinking water sourced from surface waters after flooding and heavy rainfall

Surface water from farm dams, rivers and creeks should not be used for drinking or cooking without appropriate treatment. This water may be acceptable for non-potable uses such as washing clothes, irrigation, gardening, toilet-flushing, but we recommend that water used for bathing is at least disinfected before use. It is very important to ensure that the water your family drinks is safe.

NSW Health warns that heavy rainfall and flooding increases the risk of contaminated water which could contain disease causing micro-organisms, chemicals or algal blooms, entering surface waters such as rivers and creeks.

Residents are urged to ensure they are aware of the quality of the water source they are using.  

To avoid water quality problems:

  • Disinfect your water to kill disease-causing microorganisms and to protect the water should recontamination occur. Chlorine is the most common and cost effective disinfectant used for drinking water. Drinking water can also be disinfected by bringing it to a rolling boil and then allowing it to cool.
  • Filter your water. There are a number of different filtration methods available and the choice of filter depends on the contaminants that need to be removed. Special filters may be necessary to deal with blue-green algae and specific chemicals.
  • Make sure that surface water sources are fenced against livestock, and protected from septic tank overflows and spills of domestic, agricultural or industrial chemicals.
  • Check up-stream for contamination sources. Your local Council or Catchment Management Authority may be able to provide information about nearby activities which may affect your local water quality.
  • If information on water quality is not readily available, households may wish to have the water tested for key health characteristics. Regular testing would be  necessary to identify all contaminants, especially due to varying weather conditions. 

It is worth remembering that a properly maintained rainwater tank can provide good quality drinking water. Providing the rainwater is clear, has little taste or smell and the roof, gutters and tanks are well maintained, it is probably safe and unlikely to cause any illness for most users.

Further information on water quality and treatment is available in NSW Health’s Private Water Supply Guidelines and the Rainwater Tanks brochures.

For further information contact your local Public Health Unit.

Page Updated: Thursday 6 November 2014