RESIDENTS across the peninsula have been left outraged and baffled after newly proposed mandatory planning rules suddenly labelled thousands of properties as “highly susceptible” to landslides, despite many believing they face no such risk.
The Mornington Peninsula Shire has mapped wide-spread landslide-risk areas across the peninsula after councillors approved on 17 November to advance an interim erosion management overlay – a planning control aimed at managing development on land most prone to landslides.
The move followed an urgent directive from state Planning Minister Sonya Kilkenny to prepare an amendment to the Mornington Peninsula planning scheme that would form the new control.
The overlay is intended to cover areas classified as “highly susceptible” to landslip risks – around 33,000 lots, roughly 27,000 of them residential – that are not already subject to existing erosion overlays.
The planning control was a key recommendation of the board of inquiry into the McCrae landslide in January that saw a house slide down the escarpment, which an inquiry found was caused by a burst water main.
Mornington MP Chris Crewther, who has called on the Planning Minister to urgently explain why 27,0000 Mornington Peninsula properties were suddenly flagged as being a landslide risk, described the move as an “overreach”, causing many residents to feel “deeply confused,” with many properties having “zero to no landslide risk”.
Crewther said the overlay had zoned everything from 30cm retaining walls to asphalted flat residential streets and built-up piles of garden rubbish, with flat land marked as “red blobs on the map”.
“The State Minister has the final say and should not approve this in my view in its current form,” he said.
He raised the issue in Parliament on 2 December saying thousands of residents had received an unexpected text message from the shire, issued on behalf of the Department of Transport and Planning about the new landslide planning controls, pending state approval.
“Even my own property is affected as well,” he told Parliament.
“But there are many properties right across the peninsula. They want answers now from the Minister and they want this overreach to be put back.”
He urged the minister to provide immediate explanation about the “basis, intent, implications and approval process” behind the new measure.
Mayor Cr Anthony Marsh said, “It’s important to remember that we were directed by the state Planning Minister to implement the interim erosion management overlay using the information that the shire had on hand”.
“We know that there are some areas of land that have been identified by an external firm that should not be included, and I would expect that these areas are identified and removed soon.”
Among property owners affected is Martin Scanlon, who received notice stating his Tyabb home was identified with a 1.5sqm slip zone at the front and a small section at the rear, despite being on flat, stable terrain.
He said it made no sense and was a “complete overreach and a complete reaction to McCrae”.
“It’s just ridiculous, particularly given they are using a 2012 map, and they haven’t actually come out and done a survey, they haven’t been on-site,” he told The News.
“They’re not actually following the board of inquiry guidelines, where one of the guidelines was to specify in their overlay whether the risk was low, medium or high and they’ve done none – they’ve just lumped 33,000 properties into the overlay which affects around 40 percent of the residences on the peninsula.”
Scanlon was also alarmed at what it might mean for property values and insurance saying, “I think the Minister just devalued 40 per cent of the peninsula – it’s not ok”.
A Rosebud resident said he discovered his home was classified within a landslip zone despite having a gentle slope and never being subject to flooding.
“It’s a small raise, less than a metre and there’s a retaining wall in front of it,” the resident, who asked not to be named, said.
“We haven’t had any problems for 20 years and we have never been flooded even when the rain has poured down in our driveway, which strangely enough, isn’t in the overlay.”
Another resident Steve said it was “very absurd” that a four-square metre area on his Somerville property was zoned as susceptible to landslip which he labelled as “just crazy” as a “small area couldn’t possibly be subject to landslip with just a half a metre slope on the area itself”.
“The data analysis has failed in my view.”
According to the overlay map, about half to two thirds of the Mornington racecourse has also been marked in the overlay.
The News understands that council planners were not supportive of the proposed overlay and did not wish to proceed with it, but the decision ultimately came down to senior management. It was then put before councillors at their unscheduled public meeting, where all voted in favour except Cr Andrea Allen.
The Minister has until 1 January to respond to Crewther’s question raised in Parliament.
First published in the Mornington News – 16 December 2025