The High Court has dashed the hopes of further compensation for victims of the disastrous 2011 Brisbane and Ipswich floods.
Thousands of people joined a class action after their homes were inundated when water from the Wivenhoe dam was let go to protect the dam wall.
The case targeted the dam operators and included Seqwater and SunWater.
At the heart of the case was whether the dam operators and two engineers who made the crucial decisions had breached their duty of care when managing the Wivenhoe and Somerset dams.
The New South Wales Supreme Court heard the case over 130 days, with thousands of documents tendered.
Round one went to the flood victims after the court found Seqwater was vicariously liable for the actions of the two engineers who were found to have not followed a manual they had helped develop.
That led them to release large volumes of water at the height of the flood, damaging more properties.
The judge found that more than 6,500 victims whose homes or businesses were damaged were entitled to almost $900 million in compensation.
In February 2021, SunWater reached a settlement of $440 million to be distributed to the victims.
However, Seqwater pressed on, winning an appeal in September.
'No further avenues for appeal'
On Tuesday, lawyers for the victims failed to convince the High Court that it should hear a challenge to the Appeal Court ruling.
Lawyer Rebecca Gilsenen, from Maurice Blackburn Lawyers, said the decision was deeply disappointing.
"We are very sorry to say that the High Court refused to grant special leave [to appeal]," Ms Gilsenen said.
However, she said, the earlier settlement was continuing.
"The settlement with SunWater and the State of Queensland stands and we will continue working hard to distribute the settlement proceeds as quickly as possible," she said.
"We know that this is a deeply disappointing outcome after an extraordinarily long journey for everyone affected by the floods."