Women bore the brunt of the voluntary work needed after the Lismore and Northern Rivers flood, University of Newcastle research shows.
The research revealed that the community's response was "spontaneous yet hugely sophisticated in its mobilisation".
Lead author and social worker, Associate Professor Wendy Foote, said the community rallied to "save itself" when the state government failed to adequately respond to the disaster.
A/Prof Foote said females filled "the huge gap left by the government's inability to respond to the event".
Researchers interviewed people from the Northern Rivers community nine to 12 months after the flood, which occurred on February 28, 2022.
Their report, to be released on Tuesday ahead of the two-year anniversary, said the devastation included the loss of more than 4000 homes and property, along with livestock and native animals.
The study's participants "all lived through the floods and witnessed government agencies failing to respond adequately to the crisis".
"Community members spontaneously worked together to save lives and manage the aftermath of the floods," the report said.
"This and ongoing unsafe living conditions resulted in flood trauma at an individual, family and community level.
"There was a community-wide experience of trauma and associated mental health impacts."
A/Prof Foote said the findings were an important representation of a region still grieving.
"We know from the 2022 NSW Floods Inquiry that there was a gross failure of preparedness and negligence in the support offered to the Northern Rivers region," she said.
"It's imperative we continue to advocate for better policies and procedures to prevent the same failures ever happening again."
The report's recommendations included giving priority to "the safety needs of vulnerable populations, including women and children, at all phases of disaster preparedness and post disaster responses".
It also recommended government funding of "essential disaster-related work" done by volunteer and community organisations.
The report's co-author Professor Margaret Alston said women historically "bear the burden" of the labour and health impacts of disasters.
Professor Alston said this wasn't aimed at diminishing the efforts of men in these circumstances.
Women often take on "nurturing or support roles" in response to trauma.
She said women did "the bulk of unpaid work in the immediate response" to the Northern Rivers flood and "stayed in support roles for extended periods".
The researchers called for a disaster fund to acknowledge the "huge personal and monetary losses" that volunteers suffer in this type of work.
