Payouts for victims of the 2011 Queensland floods are being delayed because just 1 per cent of claims involved in the long-running class action cannot be finalised.
In an update to more than 7,800 claimants, which has been seen by the ABC, those involved in the court case were told final sums will now be paid between July and September this year.
Despite a settlement sum of $440 million being ordered by a court two years ago, the update letter said all claims will have to be assessed before final payments are disbursed.
From June last year, interim payments were made to those involved in the class action.
"The reason for the delay in making final payments is that the very small number of claims that are still being assessed are the most complex of the claims and they are taking a bit longer to finalise and in some instances we and the assessors … have had difficulty contacting and getting the information we need from some of the claimants," the update from law firm Maurice Blackburn read.
It also warned it was important for claimants whose claims are still being assessed provide the information requested as quickly as possible.
"Please do not wait until the last date to take a step that is asked of you," it said.
Principal lawyer Rebecca Gilsenan said some claims had not been finalised because they are particularly complex but others were being delayed because participants had failed to provide basic information, including bank account numbers.
Other claimants have died and their estates have not been finalised, while several people cannot be contacted.
The law firm will be forced to exclude difficult claimants by June 2023 if they don't provide details required to finalise the action, which was commenced in court in 2014.
'This is their last chance'
Ms Gilsenan said the claims are being assessed on a rolling basis but once all the claims are finalised, they will be sent to an external auditor before being paid out.
The payments range from hundreds of dollars to millions.
"We can't pay a single claimant their final payment until every last claim is finalised," Ms Gilsenan said.
"For people who haven't provided the information required or who have dropped out of contact, this is their last chance because we're going to have to exclude those claims in order to pay the vast majority.
"We don't want to exclude people but at a certain point we must reject people from the pool, if there has been non-compliance, in order to pay those final payments."
In 2019, the NSW Supreme Court found flood engineers operating the Wivenhoe and Somerset dams in Queensland were negligent during the large-scale flooding event in 2011.
The long-running class action alleged the dam operators failed to follow their own manual and did leave enough space for heavy falls during the crucial days of rain in January.
They argued that as a result, there were heightening flood levels and damaging more properties.
Dam engineers have since spoken out about their role in the disaster.
While the court ruled in favour of the negligence claim against the Queensland government of the day, as well as Seqwater and SunWater, they were not successful in some other aspects of the case.
In 2021, the NSW Supreme Court approved a partial settlement with SunWater and the State of Queensland.
At the time, the law firm said the $440 million settlement covered 50 per cent of the liability for the losses suffered by group members.
