Dirty water turbidity at Mt Crosby water treatment plant. Photo: Supplied
Directors-general of three state government departments have been called in to urgent meetings to discuss the threat which silt in the Brisbane River poses to Brisbane’s water supply.
Read the Generator post that brought the problem to the Brisbane media’s attention.
Read the original at Brisbane Times
Deputy director of the Australian Rivers Institute Professor Jon Olley yesterday warned the Mt Crosby Water Treatment Centre could again be clogged with silt in the next “very heavy” rain.
During January’s flood, Brisbane came within six hours of running out of treated drinking water because the river sediment blocked the Mt Crosby Water Treatment Plant.
Professor Olley recently inspected river banks in the Lockyer Valley, where the silt came from, and found they had been badly damaged in the 2011 and 2013 floods.
He said it was extremely likely the Mt Crosby Water Treatment Plant could be blocked again if there was another bout of heavy rain.
Water Supply Minister Mark McArdle said on Thursday night he was waiting on a Seqwater report to explain the implications of the treatment plant’s failure.
“That report will show exactly why it failed, or could not operate,” Mr McArdle said.
“And it may well be that the catchment, or catchments are in a state that need to be looked at.”
The report is due in a few weeks, he said.
His office also said directors-general from the Environment, Energy and Water Supply and Natural Resources and Mines departments had an urgent meeting on Thursday to discuss the matter.
Several sources yesterday agreed with Professor Olley’s warning, pointing to the Seqwater graph (above) which shows an increasing amount of sediment in the Brisbane River.
The tallest spike represents a four-fold increase in water turbidity (suspended solids) at Mt Crosby after the Australia Day floods of 2013.
The second highest spike is the water turbidity after the January 2011 floods, while the third highest spike dates back to heavy storms in November 1995.
Sources are very concerned that the frequency of heavy rain events is increasing and that there is problem with badly-eroded streams and banks in Brisbane’s upper catchments.
Sources – from within three departments – agree it is time for a renewed catchment approach, but are unsure of their roles within their departments.
Mr McArdle said two forums held in Brisbane next week on developing a 30-year water strategy for Queensland would discuss sediment problem.
“There is no doubt about the fact that catchments are a very important part in the delivery of water to the water treatment plant and how they operate can be very important to the quality of water that is finally produced,” he said.
Mr McArdle said he was happy with the working relationship between the departments of Environment, Energy and Water Supply and Natural Resources and Mines over the issue.
A spokeswoman from Minister for Natural Resources and Mines, Andrew Cripps said no permits had been issued for extracting sand and gravel in the Lockyer Valley.
“Rather, material is being moved around within damaged sections of watercourses to try to rebuild infrastructure and stabilise severely damaged banks,” she said.
The spokeswoman said this rebuilding work would not contribute significantly to sediment in the river.
Brisbane Lord Mayor Graham Quirk – as the president of the South East Queensland Council of Mayors – called for the state government to provide policy advice on the issue.
“I think it is up to the state government in many ways through Seqwater to tell us that it is a serious problem,” he said.
“If there is a recognition that there is a problem, then we need to work in partnership to solve that problem.”
The Council of Mayors, originally a lobbying body for infrastructure funds, has broadened its agenda to include stream catchment issues.
Councils upstream from Brisbane are members of the Council of Mayors.
Mr McArdle said he had no desire to tell councils how to manage their catchments.