Advice to the Queensland Government on purified recycled water 

On 26 November 2008, the Queensland Government confirmed that it would adopt an emergency trigger for the introduction of purified recycled water into Wivenhoe Dam. 

The Government had requested that the Queensland Water Commission provide urgent advice on the trigger for the use of purified recycled water, should the Government confirm it would be used only as an emergency source to augment drinking water supplies.

The Commission advised the Government that misleading and false information, which has been reported without foundation, has impacted community confidence in this new source of water in recent weeks.  However, the Commission remains confident that purified recycled water continues to represent a safe and reliable source of supply which poses no additional risk to our drinking water.  Having reviewed the scheme design and testing results currently available, the Chair of the independent scientific Expert Advisory Panel, Paul Greenfield AO, has publicly expressed the same confidence.

Given the scientific evidence, South East Queensland’s water security would clearly be increased if purified recycled water were used as a permanent and ongoing source of supplementation to Wivenhoe Dam.  This reflects its benefits as a climate resilient source of supply in a time of significant population growth and latest analysis shows the region’s existing storages can be relied on to provide a yield which is 30% (or over 200,000 ML per annum) less than their historic yield.

The Commission also advised the Government that, if purified recycled water was used as an emergency supply only, the trigger level for its introduction into Wivenhoe dam would be when combined SEQ dam levels (Wivenhoe, Somerset and North Pine) drop to 40%.

This followed detailed analysis of the impact on the drought storage reserve of delays to Traveston Crossing Dam Stage 1 and a decision that purified recycled water would not be used to augment Wivenhoe Dam until the trigger had been met.  This assessment indicates that the drought response trigger would need to be increased to more than 38% of the combined capacity of Wivenhoe, Somerset and North Pine dams. The system yield and Drought Storage Reserve would change once Traveston Crossing Dam Stage 1 is commissioned.

Read the full report (PDF, 1.17MB)

Community confidence

The Commission has also undertaken market research on the community’s awareness of purified recycled water. The findings show that community support for purified recycled water has decreased over time. In early 2007, adding purified recycled water to Wivenhoe dam was supported by 75% of the community. Currently, research shows it has 55% support and a further 39% are opposed to it. Two thirds (66%) of SEQ residents believe it should be excluded if dams reach a certain level. Of those 66%, 30% say the dam should be 50% full before we should stop adding purified recycled water and 29% say the dam should be 75% full before it should be stopped.