There was a bright spot amid the solemn storm clean-up that began in Sydney yesterday afternoon.

“She’s alive,” Natali Pearson screamed. “I can’t believe it, Jasmyn survived.”

Five hours earlier a torrent of water had ripped through Ms Pearson’s mother’s home on Sydney’s north shore, turning the backyard into a lake.

Ms Pearson had received a one-word text message – “HELP” – from her mother Sheridan Rogers in the morning and raced over to pick up the pieces.

Parts of the city received more than a month’s worth of rain in an hour as the deluge caused chaos on roads and sparked more than 1500 calls for help to the NSW State Emergency Service.

But amid the carnage – and the thousands of dollars worth of damage to Ms Rogers’ home – there was something to smile about.

Jasmyn the fish was in the nextdoor neighbour’s yard, flapping about and clinging to life.

Jasmyn the goldfish was found alive, just. Photo: ABC News/Mridula Amin

The flash flood was so powerful it lifted Jasmyn from her home in Ms Rogers’ pond and dumped her over the fence.

“Quick grab a bucket,” Ms Rogers yelled to Billy Gleeson, who lives three doors up.

A Champagne cooler was the first thing they could lay hands on, and Jasmyn was swiftly delivered back to her home.

“My granddaughter is going to be happy,” Ms Rogers said, as Jasmyn was reunited with some of her friends.

“The fish is named after her.”

Ms Rogers (R) and her daughter were all smiles when they discovered the fish alive. Photo: ABC News/ Mridula Amin

The moment was a bright spot in an otherwise dark day for an unlucky group of residents on Lytton Street in leafy Cammeray, who were among the worst hit by yesterday’s storms.

Four properties there were swamped by a freak flash flood that burst through backyards and into homes.

Sarah O’Callghan woke up to find her living room under water.

“I couldn’t believe it,” she said, pointing to the high-water mark on her wall.

“I heard the water gush through the backyard, it took about five minutes to fill up and came inside.

“There was nothing I could do.”

The flooding at Sarah O’Callaghan’s house yesterday morning. Photo: Supplied/Sarah O’Callaghan

Next door, Michael Flude was waiting for his insurance company to arrive.

“Don’t worry about that,” he said, as visitors attempted a polite foot wipe on the welcome mat outside his front door.

“You don’t need it.”

It soon became apparent why.

Mr Flude’s lounge room looked as though it had been ransacked by a large group of muddy burglars.

His soggy sofa was in the kitchen, surrounded with portable fans.

Their puffing was not making much difference.

Lytton Street locals ditched their soggy shoes as the day went on. Photo: ABC News/ Mridula Amin

“The water was so powerful,” Mr Flude said.

“It was extrodinary.”

The damage on Lytton Street was caused by a temporary river that developed near the top of a nearby park and swept downhill.

The force was so strong it ripped gates off their hinges, and flooded the laundry complex of an apartment block.

Back at Ms Rogers’ place, the search for fish continued – this time underneath the house.

“There’s more, I’ve found some,” Ms Pearson shouted.

Her mother managed a smile and a laugh, as she carefully placed another batch back in her pond.

There were still 13 missing.

This laundry was a mess after the flooding ripped through. Photo: ABC News/Mridula Amin

“Oh God,” Ms Rogers said, looking underneath her house.

“How are they going to get the water out from under there? My air-conditioning and heating system is gone.

“It’s just a freak thing. I’ve never seen anything like it.”

If she had not already forgotten the incident, no doubt Jasmyn the goldfish would agree.

Despite being carried under the house by flood waters, most of the fish were returned safely. Photo: ABC News/ Mridula Amin