Sydney homeowners left with hefty cleanup bill over burst water main

Residents in Baulkham Hills in Sydney's north-western suburbs woke this morning to find water rising around their beds after a water main burst.

Thousands of litres of water gushed out over Palace Road and through neighbouring homes.

Residents fled their homes dressed in their pyjamas, emergency workers taking an hour to stop the flood.

Locals described to 9NEWS the loud noise of the enormous gusher.

One woman by the name of Joanne said it was loud and "like a rushing torrent".

"It was just gushing ... when I looked down the backyard and it was just going everywhere," resident Sofia Edwards said.

By daylight the true extent of the damage became clear, with a trail of leaves and silt left behind.

The water came down with force, bringing with it mud and debris, turning backyard swimming pools into swamps.

Resident Jane Lambert said when she got out of bed there was water around her ankles.

"I opened up the front door and my shoe just went flying, sailing down the driveway and I had to go running after it," she said.

"I haven't slept and I've cried for about five hours."

Sydney Water spent today working to fix the broken main and to find out why it happened.

"Typically in this time of year the change in the weather might move the ground, that might put extra force on the pipe and there might have been a hidden weak spot that breaks," Sydney Water spokesman Gary Hurley said.

It is not the first time the street has flooded, the same pipe broke eight years ago.