Storms could worsen landslide that tipped house over seaside cliff

Melbourne IT entrepreneur Nick Moran owned the property at 3 Penny Lane that was destroyed in the landslide. On Tuesday, he said his wife and daughter had narrowly escaped during another 30 tonne landslip that damaged the house a week earlier.

Several neighbours told this masthead that they had been pleading with Mornington Peninsula Shire and South East Water for years to address water issues near their homes.

Professor David Kennedy, an expert in physical geography from Melbourne University, said parts of McCrae and nearby Mount Martha were vulnerable to landslides.

“It’s an old sea cliff that they’ve built on. It would probably be 5000-6000 years old, that’s why it’s already very steep,” Kennedy said.

Kennedy added the cliff was cut into granite rock that was old, weathered, and breaks down to a coarse sand clay that is unstable. Once a large volume of water was added – either via a major rainfall or below groundwater flows – it could cause a landslide, he said.

“That recent rain event would definitely have lubricated everything really well,” Kennedy said, referring to a major downpour during a storm on Sunday.

He added it was also likely, based on witness reports that water was flowing from the ground, that underground water was also involved.

On other occasions, Kennedy said he had seen soak holes – a hole under a property on a slope used to capture rainwater drainage – contribute to landslides, particularly after heavy rain.