Warnings issued late in Brisbane floods

His review of the official response to the floods, which killed 14 people and damaged thousands of homes across the southeast, was released on Tuesday.

"The experience within the community, reflected by respondents, suggests that warnings to evacuate came too late, with houses already flooding up to a day and a half before that warning was issued," Mr de Jersey's report said.

"There seemed to be some delay in the review and approval by QFES (Queensland Fire and Emergency Services) of the wording of the EA (Emergency Alert) and timing of the issue of the EA."

The probe found that warnings through social media, mainstream media and emergency systems caused confusion with the "inconsistent and confusing" messages broadcast. 

"Some of these communication channels were not accessible by all, and loss of power and digital illiteracy meant some residents found it difficult to stay informed," the report said.

"Some commented that the multiple channels and likely the speed at which each one could be deployed meant that sometimes the messages were inconsistent and confusing."

Mr de Jersey, a former chief justice, has made 37 recommendations, including a review of the flood alert system to find a more efficient way to distribute mass warnings.

He also recommended the flood resilience home program be continued and stormwater backflow prevention devices be installed.

Brisbane Lord Mayor Adrian Schrinner promised the council would implement all 37 recommendations.

"We'll be getting on to make sure these lessons are learned," Cr Schrinner said on Tuesday.

He said it was Brisbane's biggest three-day rain event with more than 20,000 properties across 177 suburbs impacted by a combination of river, creek and overland flooding.

"This event prompted the biggest-ever clean up of our city with more than 60,000 tonnes of flood-impacted belongings removed from over 3000 streets during our special flood edition of kerbside collection," Cr Schrinner said.