Landslip Risk AssessmentYarra Ranges

Hillsides, landslips and debris flow

The Yarra Ranges includes the Dandenong Ranges, valley slopes and foothills with differing terrain and ground conditions. A suburb name or a broad regional map cannot establish the conditions beneath an individual property.

Debris flow is a form of landslide in which a mixture of water, soil, rock and other material can move rapidly downslope, often along a drainage line. It can affect land below its starting point. Understanding the surrounding slope and drainage setting can therefore matter as well as the proposed building location. Council’s mapping review distinguishes landslip susceptibility from debris-flow susceptibility.

Which assessment category applies?

For permit applications, the schedules identify the following categories. The table summarises their wording; it is not a list of interchangeable report packages.

The existing EMO refers to the March 2023 incorporated document. EMO3 and EMO4 refer to the October 2025 interim document. These documents explain the assessment requirements and circumstances in which further assessment or written geotechnical advice is appropriate.

The word ‘and’ in EMO4 is significant, but it does not necessarily mean two separate reports: the interim incorporated document allows the Geotechnical Assessment and Landslide Risk Assessment to be reported together. Council also has discretion under the schedules to waive or reduce an application requirement that is not relevant.

Check the whole proposal against the map

Use a current planning property report to identify the overlay affecting the land, then compare the mapped area with the proposed site plan. Include access, excavation, filling, retaining walls and drainage changes, rather than checking only the dwelling footprint.

Where onsite wastewater disposal is proposed, its location and relationship to slopes and drainage may also be relevant. If more than one landslip-related overlay affects the site, the applicable requirements need to be considered together. The interim incorporated document provides for a single assessment addressing overlapping controls.

Existing controls and proposed changes

At the review date, interim EMO3 and EMO4 were operative. The Planning Schemes Portal recorded Amendment C225yran as ‘Approval Under Consideration’. Its proposed permanent mapping and schedules should therefore be distinguished from the controls currently applying to a property.

Check the current scheme again when preparing an application, particularly if earlier advice was based on proposed mapping.