The state government will not lower water levels at the Wivenhoe or North Pine dams ahead of the upcoming summer wet season.
Water Supply Minister Mark McArdle said he made the decision after studying reports from the Department of Energy and Water Supply, the Bureau of Meteorology, the South East Queensland Water Grid Manager and the Queensland Water Commission.
"Taking into account the difference between the current seasonal forecast, the 2010-11 forecasts, as well as drinking-water security for southeast Queensland, I have decided not to lower Wivenhoe or North Pine dams at this time," he said.
Mr McArdle said he sought advice from the weather bureau on November 1 about the 2012 to 2013 wet season.
"It's clear from BoM's latest advice that this summer's wet season is different from the strong La Niña conditions that persisted during the devastating Queensland floods of the 2010-11 wet season," he said.
Mr McArdle said he also requested further advice from the Department of Energy and Water Supply on seasonal weather forecasts, water supply security, dam operations and the extent to which lowering the dams was likely to mitigate the impacts of a potential flood, after the bureau gave a presentation to cabinet in September.
"Wivenhoe Dam was designed and constructed to operate as a dual-purpose water supply and flood mitigation dam, and its dedicated water supply compartment is always less than half of the dam's total capacity," he said.
The dam is at its "full supply level" — referred to as 100 per cent — when only its water supply compartment is full.
The water supply compartment accounts for about 45 per cent of the total dam capacity, with the rest reserved for about 1.42 million mega litres of flood storage.
Wivenhoe Dam's water supply compartment is currently at 96.5 per cent capacity, while North Pine Dam's is at 96.5 per cent capacity.
Wivenhoe Dam's role in Brisbane's January 2011 flood came under scrutiny at the commission of inquiry, with critics arguing that more water should have been released sooner.
In July last year, the commission issued a report from independent hydrological expert Mark Babister, who concluded Wivenhoe engineers achieved close to the best possible mitigation during the January floods.
This was despite 59 per cent of floodwaters in southeast Queensland coming from dam releases.
After the bureau’s cabinet briefing in September, Premier Campbell Newman said it was unlikely Wivenhoe Dam would be drawn down to 75 per cent capacity.
While floods were a key part of the Queensland wet season, widespread floods were less likely, the bureau said.
Queensland has been on track for above-average temperatures, with the southeast set for a typical thunderstorm season with a greater proportion of hail and damaging wind events compared with the previous two years.