The Queensland government says a new water release strategy for Wivenhoe dam could spare Brisbane from future flooding.

Some Brisbane Valley locals are happy to be isolated for longer during a flood if it means saving hundreds of homes downstream in Queensland’s capital.

The state government wants to rewrite the manuals of Somerset and Wivenhoe dams so more water can be dumped earlier during a major deluge.

Operators would no longer have to consider keeping six rural crossings open in the initial stages of a disaster.

It means that bridges in the valley, 30km upstream from Brisbane, would go under sooner and residents would be isolated for longer.

Modelling shows the plan would reduce the flood peak in Brisbane by 10 per cent and save between 500 and 1500 homes from flooding.

It’s also hoped that insurance premiums would be reduced.

Karana Downs local Linda has lived on the river in the valley for eight years.

Despite being fully isolated for five days during the 2011 floods, she would rather the sacrifice of a few to save the many.

“We’re near three river crossings, we decided to live here,” she told AAP.

“I’d rather the inconvenience of me having to travel further or being isolated, than people having their homes flooded.”

Neighbour Sylvia Johnson said there was no easy way for the government.

“I don’t see how they can win, it’s a lose-lose situation,” she said.

The government would consider building one bridge at Colleges Crossing with money raised from proposed asset sales.

In 2011, Wivenhoe dam banked too much water and authorities were later forced to make massive releases quickly.

About 22,000 properties in Brisbane were inundated.

Premier Campbell Newman said he hoped insurance companies would take note of the new modelling.

“It could provide premium relief for up to 1500 properties,” he said.

Ipswich Mayor Paul Pisasale said faster water releases were the right way to go, given the conditions surrounding the 2011 flood should never have been allowed.

“What happened in 2011? They opened all the gates up and said: ‘You defend yourself, city’,” he said.