The modelling will provide more accurate information to residents and businesses about the flood risk of their properties. It identifies land that may be subject to flooding from waterways, run-off from roads, footpaths and buildings, as well as climate change impacts.
Based on the modelling, councillors will consider Amendment C384, which seeks to make changes to the Melbourne Planning Scheme to include updated inundation overlay maps and planning controls for parts of the City of Melbourne.
Lord Mayor Sally Capp said the new flood modelling and planning amendment will provide the most accurate data for property owners to determine their flood risk and also ensure new developments are designed to be more resilient in the future.
"Flooding can put your safety at risk and severely damage property so that's why it is important we provide our residents and businesses the most accurate and up-to-date flood modelling," the Lord Mayor said.
"This new flood modelling will ensure the best data is used for new projects and it will also inform the City of Melbourne in terms of any future changes that can be made to make our city more resilient.
"Climate change is also likely to contribute to more intense and frequent extreme weather events into the future such as flash flooding."
City Planning Portfolio Lead, Deputy Lord Mayor Nicholas Reece, said the modelling will be vital to ensure new developments are designed to be more resilient.
"This new data will show what sites across the municipality are expected to become inundated in a range of scenarios such as run-off from roads and drains in heavy rainfall or more widespread flooding across the municipality," the Deputy Lord Mayor said.
"Developers will now have the most up-to-date and accurate data to ensure their designs take into consideration all the potential impacts of flooding on a particular site, which will make new buildings more resilient.
"The new mapping accounts for the probability of a major flood event, which has a one per cent chance of occurring in any given year. It also accounts for an 18.5 per cent increase in rainfall intensity by 2100 due to climate change.
"There hasn't been an update to flood mapping and flood-related planning controls since the early 2000s so this detailed modelling is timely to help protect lives and properties.
"We appreciate that current residents may be keen to know how this impacts them and their property, and if the planning amendment is endorsed, we will actively engage with those impacted and we will make the information easily accessible for anyone interested in knowing more."
The Good Design Guide for Buildings in Flood Affected Areas in Fishermans Bend, Arden and Macaulay will be considered alongside Amendment C384. It has been prepared in partnership with Melbourne Water and the City of Port Phillip to set the framework for creating new, flood resilient communities.
"The new design guide shows that climate change and increased flooding events will not be a barrier to outstanding architecture and building design in Melbourne," the Deputy Lord Mayor said.
"Indeed, some of the world's most beautiful cities, such as Venice and Amsterdam, have successfully managed regular flood events for centuries alongside innovative and resilient building design."
Councillors will consider the amendment and design guide on Tuesday. If endorsed, authorisation will be requested from the Minister for Planning to prepare and exhibit the amendment for community feedback.
Subject to Ministerial authorisation, it is anticipated the amendment will be publicly exhibited in late 2021.
Stormwater management is currently integrated into all City of Melbourne capital works projects.