Amendment C91 - Moorabool flood management

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Amendment C91 – Improving flood management in Moorabool Shire

Moorabool Shire has prepared Amendment C91 to the Moorabool Planning Scheme. This was at the request of Melbourne Water as the relevant floodplain management authority.


Amendment C91 details:

  • Seek to apply the Land Subject to Inundation Overlay (LSIO) and the Special Building Overlay (SBO) to land affected by a 1 in 100-year flood event.
  • Within the catchments of the Werribee, Lerderderg, and Little Rivers, in the eastern half of Moorabool Shire.
  • The Victorian Floodplain Management Strategy (2016) highlights the importance of using planning controls to help avoid and minimise flood risks. State and local planning policies require flood-prone land to be identified and managed.


LSIO and SBO planning scheme provisions explained

  • Identify land subject to flooding and trigger the need for a planning permit for proposed subdivisions, buildings and works.
    • Some permit exemptions are available for minor buildings and works.
  • LSIO applies to land affected by flooding associated with waterways and open drainage systems in both urban and rural areas.
  • SBO applies to land affected by flooding associated with overland flows from the urban stormwater drainage system.


Objective of each overlay

  • Consider the flood risk at the beginning of the development process.
  • Ensure that areas at risk of flooding are shown on planning scheme maps. 
  • Ensure that a new development maintains:
    • The free passage and temporary storage of floodwaters
    • Minimises flood damage
    • Compatible with the flood hazard
    • Does not cause any significant rise in flood level or flow velocity


All planning permit applications under the LSIO or SBO will be referred to Melbourne Water as a determining referral authority. Melbourne Water will assess development proposals and provide a referral response (including appropriate permit conditions) to Council.

The LSIO and SBO are based on detailed flood modelling and flood extent mapping undertaken by Melbourne Water.


Amendment C91 implements the findings of the 3 flood studies:

  • Report for Bacchus Marsh Area Floodplain Mapping
  • Ballan Township Flood Study Final Report
  • Lower Lerderderg Catchments Flood Mapping Report


The Melbourne Water Planning Investigations Models which prepared flood extent mapping for rural areas not covered by the flood studies.

The peer review of this body of work commissioned by Council in 2017.


To find out more about Amendment C91, or to make a submission, go to our ‘Have your say' page.


Planning Panel

Exhibition of Amendment C91 closed on 18 August 2020.  On 3 March 2021, Council considered the 41 submissions received and resolved to refer the submissions to an independent Planning Panel.

Last Updated:

Monday, 18 January, 2021 - 10:39