Aussie homes ruined by rooftop high wall of water smashing into them when government pipe burst - and why it could happen again

Residents were forced to evacuate their homes after they were flooded when a torrent of surging water from a burst government pipeline hit them.

The large water main connected to a major Sydney dam split around midday on Friday at Como, in the city's south, drenching nearby homes in Binya Place and Inelgah Road which became inundated with water.

Fences were toppled over, windows smashed and backyards were washed away at the hardest hit properties.

One resident, Michelle Bunch, said she feared her home could end up waterlogged with extensive damage.

'It was smacking against the windows, we thought they were going to smash apart,' Ms Bunch told Nine News .

The Sydney Water maintained pipeline connects to the Woronora Dam which supplies water to several suburbs south of the Georges River including Sutherland, Cronulla, Engadine, Heathcote, Helensburg.

It, like most water pipelines in Australia largest cities, has been around for well over half a century, being laid in 1942, with researchers from the University of Technology Sydney saying the average age of our water infrastructure is 80-years-old.

The deluge forced part of the roof on Ms Bunch's property to collapse and destroyed some of the family's belongings.

The destruction has forced them out of their home and they will have to find alternative accommodation.

'It was pretty terrifying,' Ms Bunch said.

A Sydney Water spokeswoman told Daily Mail Australia crews from the agency isolated the main and repairs are currently underway to fix the pipe.

'Network Technicians were on site assessing a leak on the main when it burst,' the spokeswoman said.

'Customer advocates are on site working with impacted customers and assessing the damage.

'Sydney Water apologises for the inconvenience caused to our customers.'

NSW State Emergency Services said some homes had been severely impacted by water damage while others sustained only superficial damage.

Australia's 140,000kms of water pipes are on average 80-years-old with the aging network prone to faults.

Professor Fang Chen and Associate Professor Yang Wang lead an award-winning team of scientists in the UTS Data Science Institute which are researching ways to identify potential ruptures before they happen.

'Just like a human octogenarian, this infrastructure needs closer monitoring and ''preventive medicine'' to keep it going strong,' Professor Feng said.

Collaborating with more than 30 utilities in Australia and internationally, they've examined 1 million pipe failure records for 10 million pipes over the past decade.

The team has developed a computer-driven model to predict where faults are most likely to occur before the infrastructure breaks.

On Friday, residents reportedly informed Sydney Water about 6am that a hissing sound was coming from the pipe before it ruptured.

The agency inspected the site at 7.30am and it is understood they fixed the issue.

However, the pipeline to burst open just hours later.

The cause of the rupture has yet to be confirmed.

Sydney water is the main supplier of drinking water across the Harbour City and the agency services five million customers.