Wivenhoe release to keep city under water

Brisbane flood emergency to extend into next week as Wivenhoe Dam unleashes millions of litres of water for six more days.

Brisbane’s flood emergency will extend into next week as the government-owned operator of the Wivenhoe Dam unleashes millions of litres of water through the city for another six days.

Tens of thousands of people displaced from low-lying homes will remain stranded while the dam’s 2.08 million megalitre emergency compartment is ­emptied in case of further rains.

The dam on Tuesday was holding what was classed as “170 per cent”, with its maximum capacity being 200 per cent. Dam engineers plan to reduce capacity to 100 per cent by Monday.

The Brisbane River was set to hit 2.8m because of a high tide on Tuesday night, after reaching 3.33m earlier in the day, down from 3.85m on Monday.

While blue skies stretched across southeast Queensland on Tuesday, major rivers and creeks continued to flood. The Bureau of Meteorology has forecast a return storms later in the week.

SEQ Water external relations manager Mike Foster said flood levels were not expected to ­go past Monday’s peak during upcoming releases. “People will not see significant rises in those river levels over the next seven days, certainly it won’t be causing any flooding downstream,” he said.

But the releases will keep the river topped up, prolonging the length of the disaster, which has flooded an estimated 15,000 homes. Brisbane couple Stewart and Sarah Selwood thought changes made after the 2011 disaster would have helped prevent flooding this time, but that didn’t stop Oxley Creek from rising into the first floor of their home.

“We thought we would get some flooding but we put a lot of boxes downstairs on the table ­because we didn’t think there could be as much rain as there was,” Ms Selwood said.

“I think after they said they did all of the work on the drainage and the dam outletting that it couldn’t happen again on this scale.”

SEQ Water has discharged millions of litres of water since ­releases began on Friday night, timed with Brisbane’s low tides. But it has faced criticism for not acting sooner when heavy rains were first forecast last Tuesday.

Mr Foster said “there was ­absolutely no reason for us to consider early releases”, despite warnings from the Bureau of Meteorology of heavy rain.

“When this event started Wivenhoe Dam itself was just over half-full so we had all that capacity, plus our flood compartment available,” he said.

Premier Annastacia Palaszczuk insisted the dam had “done its job” and mitigated the scale of the crisis.

Wivenhoe Dam was built in the 1980s to defend Brisbane after a 1974 flood left 14 people dead and 8000 homeless.

In 2011, emergency releases from the dam were blamed for 80 per cent of the flooding that ravaged Brisbane.

The flow rate out of Wivenhoe Dam on Tuesday was slower than during the 2011 floods, when water was dumped at 7000 cubic metres a second. Thanks to easing rain, engineers have kept the flow rate at about 3250 cubic metres a second, which still causes flooding to low lying areas.

Mr Foster said SEQWater could not delay dam releases to allow river levels to subside first.

But the BOM warned southeast Queensland “is not completely out of the woods yet”, with storms forecast for Thursday.

Additional reporting: Charlie Peel