TOWNSVILLE, AUSTRALIA (NYTIMES) - On the 12th day of rain, Ross and Kate Bennett were among the only residents on their street, where the water had risen so high that at one point, Mrs Bennett couldn't walk into her yard, lest she be swept underwater.

After the record-breaking rains subsided, they looked around: The furniture was soggy. The car was soggy. The dogs, Cuddles and Murphy, were soggy.

In street after street across Townsville, a coastal city in Australia's far north, the same story played out in the aftermath of what the authorities called a catastrophe of "unprecedented" rainfall, which brought flooding, crocodiles into the streets, sewage bubbling up out of toilets and, in one week, more water than the city normally receives in a year.

Over the course of the floods, two people died, 1,000 people were evacuated, 18,000 residents lost power and at least US$74 million (S$100 million) in insurance claims have been filed.

Yet during and immediately after the disaster, many residents rallied to help one another in ways that mental health experts said were critical for people's ability to recover from disasters and cope with future ones.

And the Bennetts, surveying the damage, were in good spirits. That day alone, they said, they had fielded around 40 calls from people eager to help them clean up their home, some of whom they barely knew.

Others wanted to thank Mr Bennett, who had spent the past few days helping to evacuate his neighbours by boat, even as his own house was going underwater.

They were not alone: During the storm, a single family sheltered 60 people and a hairdresser opened her salon to provide drinks and a place for people to dry their clothes. Locals said a blind man and his girlfriend delivered water to residents to use in place of what the floods had contaminated.

Other residents, returning home to the destruction - mildew creeping onto furniture, random objects strewn across their yards, food rotting in their refrigerators - were helped by neighbours as they began the arduous task of putting their lives together again.

Community support is the biggest predictor of how well people recover from disasters, "over and above the horrors of the trauma," said Professor David Forbes, the director of the Phoenix Australia Centre for Posttraumatic Mental Health.

Social connections, he said, were crucial.

As climate change makes it likely that disasters will become more intense and frequent, researchers are studying how communities respond, and what they need to be resilient.

Being part of a community response can be "protective," said Prof Brett McDermott, a psychiatrist at the Queensland University of Technology who has helped recovery efforts after several natural disasters, including Cyclone Debbie, which hit Queensland in 2017.

"People who get through this are stronger," he said.

Ms Helen Peatling, a 77-year-old resident, has had such support, even though the Townsville flood recalled an earlier trauma: In 1950, Ms Peatling lost her own mother in a flood, and the knock on the door from the police to evacuate "brought it all back", she said.

But on Wednesday, Ms Peatling said, she "had a really good cry", and by Thursday, the group of friends she dances swing with six nights a week were helping clean up her home.

"I've only known Helen for a few months," said Mr Rod Hardacre, a friend in her dance group. Now, he was helping to sweep the silt into her yard, and stripping her sodden carpet with a bread knife.

Not everyone has been so lucky. At the evacuation centre at Heatley Secondary College on Thursday, many residents were still unable to return home, and had not yet been placed in other short-term accommodation. Some lay on stretcher beds, while others sat huddled in groups.

Mr Colin Strange, another resident staying at the centre because he was unable to return home, said he felt like his mind was "going funny".

Mr Chaplain Kennith, 80, sat outside with his dog, a chocolate brown mutt named Coconut.

Mr Kennith said he and his dog had been at the school since being evacuated by the police a week earlier, when 20cm of water inundated his house. The authorities had not found housing suitable for them both, and Mr Kennith said he would rather sleep on the street then be apart from his dog.

All he wanted, he said, was to "go back home".

Mr Danny Tunsin, who had come to Australia on a refugee visa from Thailand, said he had no family in Townsville except for his wife.

For people like this with fewer social connections, experts say, psychological first aid - which helps people learn how to cope with disasters and meet basic needs - is crucial.

Ms Dale Preston, the regional coordinator for the Australian Red Cross, said that for the most vulnerable, like the homeless and older people, the practical and psychological challenges of recovering from a disaster can quickly multiply. Providing support as soon as possible was important to recovery in the long run, she said.

Ms Samantha Klintworth, a general manager at Uniting Care Queensland and Lifeline, a crisis support service, said that social workers tried to replicate those social connections for people who did not have them by offering support services, and encouraging people to share their stories of coping with other disasters.

"In this instance, we have community members who were impacted by drought and are now impacted by flood," she said. "We ask them, 'Tell us how you coped during the drought.'"

But even for those who appear to be coping, said Ms Klintworth, the real danger zone is six to 12 months after a disaster strikes. It is then, experts agree, when the news coverage fades and others seem to move on, that residents who are still struggling with practical issues, like insurance claims, and emotional trauma, can feel abandoned.

Sweeping mud from her porch, the Bennetts' neighbour, Ms Betsy Parker, said she recognised this was possible. The ground floor of her home was destroyed, and she and her husband had moved in with their daughter.

"I think the thing that might hit us is down the track, when I'm getting under my daughter's skin," Ms Parker said.

On the other hand, she noted, the family was not alone in its struggle. "There's so many of us in the same bizarre situation," she said. "After this is all over, we're going to have a street party."