Our drinking water is produced from a range of sources, including open catchments such as lakes, rivers and dams. These natural sources may contain soil, pollutants, debris, and micro-organisms. 

SEQ can experience flooding during severe wet weather events, bringing widespread disruption and posing a potential risk to our water quality.  

Flood water can introduce a range of conditions that make it difficult to treat source water.  

How do floods impact water quality?

Flood events often result in large volumes of water in our catchments carrying debris, pollutants, and pathogens. Some contaminants include: 

• Sediment and turbidity – increased soil erosion leading to “dirty” water which can be challenging to process through water treatment facilities. 
• Organic waste and nutrients – increased organic material such as algae blooms which can also cause treatment challenges as well as potentially impacting the taste or odour of treated water. 
• Contaminants – chemicals, sewage, debris and industrial waste which may result in increased concentrations of pathogens and chemicals in the source water that need to be removed.

Effects on drinking water and public health 

Our water treatment plants are designed to treat water under a variety of conditions and can continue to operate safely in many situations, including storms and floods. 

In rare situations, following a significant storm or flooding event, drinking water quality may be adversely impacted due to a range of reasons. This may include a loss of power, damage to assets or poor source water conditions. If an instance occurs where one, or all, of these situations were to result in the production of unsafe drinking water a public health announcement would be made and could include a boiled water advisory notice or a do not consume advisory notice. 

It is important to understand that exposure to contaminated water may cause health symptoms such as gastrointestinal illnesses; and skin and eye infections, and Seqwater are continually monitoring the quality of its water to ensure the water you receive in your home meets the  Australian Drinking Water Guidelines.  

What is the response to a water quality issue?  

Seqwater, local water service providers, and local and state government, all play a critical role in managing post flood and storm recovery, including water quality.  

If water quality is affected, particular focus turns to:  

• Ensuring public health and safety 
• Monitoring and testing: Increased water quality assessments to identify contamination levels and adjust treatment accordingly. 
• Public safety alerts: Issuing boil water advisory notices and safety recommendations for affected communities. 
• Infrastructure repairs: Restoring power to water treatment plants and roof structures of reservoirs which may have been damaged. 

What residents can do 

To ensure safety during and after a flood, residents should take the following precautions: 

• Conserve and store clean water ahead of severe wet weather events.  
• Follow boil or conserve water advisory notices: If authorities advise boiling water, ensure it reaches a rolling boil for at least one minute before consumption. Water should be brought to the boil and then allowed to cool, before being stored in clean, covered containers before use. Take care when boiling water as it can scald. It is safest to boil water using an electric kettle. If you have lost electric power, water can be boiled using a saucepan on a gas stove, barbecue or portable gas cooker. Always take care when boiling in pots and pans, particularly if you have young children or vulnerable people in your household. 
• Report water quality issues: Contact Seqwater or your local water service provider if you notice unusual water colour, odour, or taste. 

Is your water safe to drink?  

Seqwater operates over 30 water treatment plants and provides clean and safe drinking water to SEQ.  

All source water that is treated must adhere to the stringent Australian Drinking Water Guidelines.  

The standard water treatment processes include coagulation, flocculation, sedimentation, filtration and lastly, disinfection of water.  

When conditions change due to flood water or severe weather and there are issues with water supply, the SEQ Water Grid allows treated drinking water to move around the region.  

If there is an event that impacted drinking water supply to households, public information will be issued so the community can stay informed and stay safe.

Flooding in Brisbane presents significant water quality challenges, affecting both human health and the environment. While authorities will prioritise the work to restore safe drinking water, public awareness and precautionary measures remain a crucial role in any event. By staying informed and taking appropriate actions, residents can minimise health risks and support the supply of safe quality drinking water to all households.