Emails from a Wivenhoe Dam engineering officer, leaked to The Australian newspaper, show that the dam went from 106 percent full on Friday January 7 to 148 percent full on Monday January 10.
This left the dam with little spare capacity to cope with an influx of water from severe rains, forcing a massive release of water on Tuesday, as the dam reached 190 percent capacity and came within 0.1m of triggering an uncontrolled released.
On Saturday January 8 the dam was releasing 1250 cubic metres per second (cumecs). The emails showed operators were worried about flooding in the Bremer River and destruction of bridges.
By 8.30pm on Tuesday January 11 the dam's operators had dramatically upped the rate of release to 8000 cumecs, in order to avoid an uncontrolled and potentially devastating release of water.
Floodwaters in the Brisbane River peaked on Thursday morning, about 36 hours after the massive release of water. It takes around 36 hours for waters from the Wivenhoe Dam to reach the city, according to The Australian.
A commission of inquiry will take place to examine SEQWater and investigate whether it made a mistake by letting the dam's flood compartment become too full to cope with a major influx of water.The Queensland government released the flood manual for the Wivenhoe and Somerset dams after concerns about the management of the dams were first raised earlier this week.
Several engineers speculated whether the Brisbane flood could have been avoided with better dam management.
SEQ Water Grid CEO Barry Dennien has said the dam was run according to the book and has declined to answer questions ahead of a commission of inquiry into the flood crisis.
Meanwhile, a higher than usual king tide will hit Brisbane by mid-morning, possibly flooding the bayside, riverside and nearby low-lying areas.
The Brisbane River is predicted to reach the minor flood level of 1.7 metres around 10.30am (AEST) on the city gauge, the Bureau of Meteorology told AAP.
The tide will remain high on Saturday and Sunday.
Lord Mayor Campbell Newman has urged residents to be prepared.
"As a result there could be some localised flooding as the Brisbane River continues to recede after last week's flood," Mr Newman said in a statement.
"If you live in a foreshore or low-lying area, by the river, or near a creek, please be prepared."
Council has warned those living in the CBD, Albion, Deagon, Hemmant, Lota, Newstead, Sandgate, Windsor, Bowen Hills, Wynnum and East Brisbane to be on guard.
Sandbags are available for pick up at council depots.
21 Jan 2011
This is NO SUPRISE, as corpau had obtained inside information from Brisbane prior to the mass media, and reported this on the 16th of January in the post:
This is NOT a matter of the Blame Game, BUT rather the realistic nature of government inaction, which ultimately costs lives, and costs the community in terms of economics.
The the government planners are saying that as a result of this we need a 'mini - recession'.
Another planned action by the government to ruin lives.