The picturesque Mornington Peninsula Shire faces an ongoing battle against coastal erosion, with certain areas protected by erosion management overlays, planning regulations designed to minimize land disturbance and inappropriate development in vulnerable locations. However, the suburb of McCrae, despite its documented history of subterranean water flows and susceptibility to erosion, remains devoid of such protective overlays. This absence of regulatory safeguards has thrust the issue of responsibility for land instability and resulting damage into the spotlight, particularly following a recent landslide that displaced residents and damaged properties.
Professor David Kennedy, a physical geography expert at the University of Melbourne, has extensively studied the region’s coastline and underscores McCrae’s vulnerability. The suburb’s hillside properties, he explains, are precariously situated on an ancient sea cliff composed of a mixture of hard granite and softer, more erodible earth. This geological composition, combined with the steep terrain, renders the area inherently unstable and prone to landslides, prompting Kennedy to question the suitability of the location for residential development. He further suggests that historical building practices, such as filling in natural gullies that once channeled water towards the bay, may have exacerbated the risk by disrupting natural drainage patterns and forcing water to seek new pathways, potentially destabilizing the already vulnerable cliff face.
The recent landslide has brought the issue into sharp focus for residents like Gerry and Bronwyn Borghesi, whose property was affected by the shifting earth. The couple is currently embroiled in legal disputes with the Mornington Peninsula Shire Council over the matter. They argue that attributing responsibility for landslides solely to individual property owners is unreasonable, given the well-documented history of subterranean water movement in the area, which predates the development of their property by decades. They question the scientific basis for holding them accountable for the movement of water that has been a natural feature of the landscape for generations.
The landslide triggered investigations by both the Mornington Peninsula Shire Council and South East Water, the regional water corporation, to determine the source of the water that precipitated the event. Both entities have remained tight-lipped about their findings, and the council has declined to comment on the ongoing litigation with the Borghesis. However, accounts from residents shed some light on the potential cause. A sinkhole, located several meters beneath Charlesworth Street, uphill from the landslide site, has emerged as a key point of interest. Residents reported observing water bubbling up from this location onto the road weeks before the major landslide, suggesting a potential connection between the sinkhole and the increased water flow that destabilized the earth.
The discovery of the sinkhole further complicates the already complex issue of responsibility. If the sinkhole, potentially on public land or within the jurisdiction of the water corporation, is determined to be the primary source of the water, it raises questions about the liability of the local authorities. The situation highlights the challenges of assigning responsibility for land instability in areas with complex geological histories and pre-existing water flow patterns. Determining the extent to which human intervention, through development and infrastructure, has exacerbated these natural processes is crucial to addressing the ongoing risk of landslides in McCrae.
The case of the McCrae landslide exemplifies the broader challenges faced by coastal communities grappling with the effects of erosion and land instability. The absence of protective overlays in McCrae underscores the need for comprehensive planning regulations that take into account the unique geological and hydrological characteristics of an area. Furthermore, it highlights the importance of thorough investigations to determine the underlying causes of such events and to develop appropriate mitigation strategies that address both natural and human-induced factors. The ongoing legal battles and investigations in McCrae will likely set a precedent for how responsibility is assigned in similar cases and influence future planning decisions in coastal areas prone to erosion and land instability.
