Council has conducted a Flood Mapping Study of all drainage catchments across Boroondara. The purpose of this study is to identify properties that may be affected by overland stormwater flows during a 1% Annual Exceedance Probability (AEP) rainfall event. Such events can also be referred to as 1 in 100 year Annual Recurrence Interval (ARI) events.

While these events are rare, it is important that flood risks are understood so residents and Council can plan to reduce any potential impacts. This is particularly relevant given the more intense rainfall we have been experiencing in the last few years.

As a result of the study, properties designated at risk of flash flooding will require consent from Council for new buildings or renovation and addition works.

Discussions with property owners

In October 2017 we directly contacted the owners of properties identified as possibly affected by overland stormwater flows during a 1% AEP event. For an explanation of 1% AEP see Flood study definitions.

In September 2018 additional advice was sent out to owners who purchased affected properties after the initial consultation letters were posted. Through these processes, we have attempted to notify all affected property owners of the results of the flood mapping study.

Property owners and residents were invited to contact Council to discuss the flood mapping results, provide feedback on historical flooding and make submissions for additional information or to express concern with the results. 

Concerns regarding the flood mapping study were presented to Council’s Services Special Committee (SSC) on 8 October 2018 and again on at the Services Special Committee Meeting on 13 May 2019. At the May 2019 SSC meeting, the SSC resolved that the adoption of the study should progress to an ordinary meeting of Council for a decision.

The outcomes of this consultation and engagement process were taken into consideration and some modifications and adjustments to the modelling were performed. The final study results therefore incorporate information and advice gained from property owners and residents during the consultation process.

A decision to adopt the study was made at the Council Meeting on 11 June 2019.

For more information, email [email protected] or call 9278 4444.

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