IN response to a parliamentary question, Planning Minister Sonya Kilkenny has attempted to shift blame for the flawed interim erosion management overlay back onto the shire, despite an earlier letter appearing to leave the municipality little choice in the matter.
Described by some as a major “overreach”, the interim erosion management overlay (EMO7) targets land assessed as highly susceptible to landslides, affecting about 33,000 lots. Of these, roughly 27,000 are residential properties not already covered by existing erosion overlays.
Many residents have expressed anger and confusion after their properties were suddenly included, with many believing they face no landslide risk at all.
The News has been told the overlay extends to areas such as small 30cm retaining walls, flat asphalted residential streets, built-up piles of garden waste and otherwise flat land.
The reply by Kilkenny was in response to a parliamentary question by Member for Mornington Chris Crewther asking the Planning Minister “what [are you] doing to give clarity to Mornington Peninsula residents on the basis, intent, implications and approval process of the new proposed landslide planning controls?”.
In response, Kilkenny stated on 27 January that “Mornington Peninsula Shire Council requested that I introduce an interim Erosion Management Overlay to land identified as highly susceptible landslide. This request is consistent with a recommendation made by the Board of Inquiry that examined the January 2025 McCrae landslide”.
The suggestion that the introduction of the EMO was at the “request” of the shire appears at odds with a letter from Kilkenny to Mornington Peninsula Shire mayor Cr Anthony Marsh, dated 9 October and obtained by The News.
That letter issued an urgent directive requiring the shire to amend the Mornington Peninsula planning scheme to introduce the interim overlay direction which applied to “land identified as highly susceptible to landslides in 2012 mapping and any additional area recommended by geotechnical engineers engaged by your council”.
“I request that your council act on recommendation 27 [of the Board of Inquiry report] to urgently implement an interim EMO and to commence this process by 23 October 2025, 14 days from the tabling of the report,” the letter stated.
“Depending on your council’s response to recommendation 27, I will consider intervening using powers available to me under the Planning and Environment Act 1987 to ensure my responsibilities under recommendation 28 are met.”
When the overlay was approved at the November council meeting, Marsh said the “interim control will help minimise the risks posed by development on landslide-susceptible land”.
“While an erosion management overlay would not have prevented the McCrae landslide, which was caused by a burst water main, it was a recommendation of the board of inquiry. Council has accepted the inquiry’s recommendations in relation to implementing the erosion management overlay,” he said.
However, errors in the mapping system were revealed after the plan was submitted, raising questions about the accuracy of the risk assessments and prompting significant community backlash. It remains unclear whether the shire was aware of the issues with the old mapping when the overlay was created.
In response to growing concern, councillors passed an urgent business motion on 16 December acknowledging community frustration and calling on the state government to accelerate a review of the “data errors” and mapping accuracy.
In a statement following the state government’s approval of the overlay, the shire said it was “aware of some anomalies in the mapping used for the interim erosion management overlay”.
“For example, retaining walls and other minor earthworks with an artificially steep slope have been picked up as being highly susceptible to landslides,” it said.
“The shire is working to remove these anomalies as a matter of priority and will then ask the Minister for Planning to revise the EMO7 to reflect the refined mapping this year.”
“In the interim – council will be supporting residents by waiving application and enquiry fees where EMO7 is the sole permit trigger and further geotechnical analysis and/or permit conditions are not required to address the underlying risk.”
The shire also confirmed that EMO7 was a temporary measure until a revised permanent EMO was introduced “after a comprehensive shire-wide review of landslide susceptibility data and mapping (also known as Stage 3 of council’s review and update of EMOs on the Peninsula)”.
In the meantime, the council said in many cases only a small portion of a property would be affected.
“This means development can occur in the usual way on the rest of the site not covered by EMO7, subject to any other relevant planning controls,” it said.
“If a planning permit is required, an application will likely need to include a report from a geotechnical expert explaining how the proposed development will be safe from landslide risk. However, council can vary or lessen requirements if they are not relevant to the assessment.”
First published in the Mornington News – 10 February 2026