Yarra’s streets are part of our stormwater drainage system, collecting water from adjoining properties and directing it to drainage pits and pipes which connect into the Yarra. This video introduces how the system works:
Blockages
Yarra has about 200 km of underground drainage pipes (similar to the length of roads), and approximately 10,000 drainage grates/pits. Blockages of the drainage grates, the pits, or the pipes, can lead to stormwater pooling on the street, and possibly entering onto properties. Council spends about $4m per year on capital expenditure to renew and improve drains [Source: Budget 2025/26] and spends about $270k per year on an external contractor to clean drains using a vacuum truck [Source: Annual Report 2023/24].
Integrated Water Management Plan
In 2020 Council adopted an Integrated Water Management Plan, with a vision of a water wise city in a healthy urban environment, and an objective of a resilient and effective drainage network that flows into healthy and valued waterways.
The plan describes two types of flooding:
- riverine (or rising levels of Merri Creek, Darebin Creek, and the Yarra River), i.e. managed by Melbourne Water, and communicated via a Land Subject to Inundation Overlay (LSIO)
- drainage (or stormwater pooling on streets), i.e. managed by Yarra City Council, and communicated via a Special Building Overlay (SBO)
The two distinct types of flooding can be affected by the same issues, e.g. how much water is absorbed or retained on properties instead of being directed into drains, however there are interdependencies between them. For example, if a high-intensity short-duration rain-storm occurs, then:
- if the stormwater drainage system was implausibly perfect, a lot of water would quickly flow into the river, causing its level to rise and potentially flooding properties identified in the Land Subject to Inundation Overlay (LSIO)
- if the stormwater drainage system was realistic, some drains would be overloaded and some streets would experience pooling, potentially flooding properties identified in the Special Building Overlay (SBO); also the river level would rise, but not as much
The plan includes actions to survey and renew drainage assets, and also to publish updated flood mapping via a Special Building Overlay. More importantly, the plan led to a tripling in Council’s capital expenditure on drainage infrastructure, from approximately $1 million per year to $3 million per year. The 2020-2024 Council continued the trend, gradually increasing expenditure to around $4 million per year.
Planning Panel Report
In December 2022 a Planning Panel Report considered updated floodwater maps for parts of the City of Melbourne. The report contains useful conclusions which are also relevant to the City of Yarra, including whether:
- the flood maps are justified
- drains can be improved, instead of introducing the maps
- the flood maps should be based on existing or planned future upgrades
- the flood maps have an impact on property values or insurance costs
The Planning Panel concluded that the flood maps were strategically justified, the flood maps should be introduced, the flood maps should be based on existing conditions, and that issues related to land values or insurance costs were not relevant.
The proposed flooding controls are strategically justified and are required to assist in the identification of land subject to inundation and flooding, and to minimise the impact associated with floods on the community.
The Panel agrees that maintenance and the upgrade of drainage and flooding infrastructure is important in managing flood risk. Not all flood risk can be overcome with drainage maintenance and upgrades. The Panel considers it oversimplistic to suggest new drainage infrastructure might prevent the impacts of climate change.
The Panel agrees with Melbourne Water that flood modelling and flood overlay maps must be based on existing conditions. There is no certainty about the nature or timing of the delivery of any flood mitigation infrastructure in the precinct. It is the consistent practice of flood modelling that informs planning schemes to model the status quo and not to anticipate potential future flood mitigation infrastructure. If flood mitigation measures are implemented in the precinct in the future, the flood extent should be remodelled, and any necessary changes made to the Planning Scheme then.
Several submissions raised concerns that the Amendment would reduce property values and impact on the ability to sell property or obtain financing. Others raised concerns about the potential increase in insurance premiums or difficulty in obtaining insurance coverage, because the properties would be identified as subject to potential inundation and flooding risk…Issues relating to impacts on land values, insurance and development costs from the application of the LSIO and SBO over a property are not relevant when considering the Amendment.
Impact of climate change
In 2024 the Legislative Council inquiry into the 2022 floods published their report, explaining the urgent need to update flood mapping statewide, and to use this as a basis for revisions to planning schemes, such as via Special Building Overlays (SBOs). These overlays inform prospective property purchasers or developers of the need to take likely flood levels into consideration when planning new buildings, and thus minimise the likelihood of future flood damage.
From that evidence it is undeniable that climate change is intensifying weather events and increasing the risks we face living in this country ‘of droughts and flooding rains’.
Inquiry into 2022 floods
For government, one of the most critical roles going forward is accurately and honestly informing communities about risk.
Inquiry into 2022 floods
Keeping Yarra Flood Resilient
On 9 July 2024 Council considered the updated flood maps that it had commissioned, and resolved to:
- publish detailed maps so that property owners could offer feedback
- ask Officers what future levels of investment in drainage they recommend
- investigate options to help ensure Yarra’s streetscapes are designed to reduce the impacts of increased flood levels
Deferral of adoption
On 26 November 2024 the new Council resolved to defer any decision to add them to Yarra’s Planning Scheme.
Council has a number of regulatory obligations regarding flood resilience. In order to fulfil these obligations and improve the community’s flood resilience, updated flood modelling and mapping has been prepared and a comprehensive way forward has been proposed to enable this to be embedded in decision making and advice to the community.
Officer Report 9 July 2024
Planning Panel report on flood overlays
On 16 July 2025 Planning Panels Victoria released their report into neighbouring Merri-bek’s proposed flood overlay. The Planning Panel considered the objections from some residents, which were similar to the objections we heard in Yarra.
The Planning Panel recommended that council adopt the flood overlay, and noted:
- suggestions such as ‘maintaining and upgrading [the] drainage network’ are not relevant
- There is no legal obligation on councils (as local drainage authorities) to ensure no overland flows in a [flood] event.
- Designing a system that results in no overland flows… (or upgrading existing systems…) would be practically impossible without huge disruption to urban streets and private property. It would also be hugely costly, and well beyond the budgets of local councils.
- There is no evidence that [a flood overlay] impacts the value of a particular property.
Overall, the Planning Panel refuted the claims of objectors, and encouraged council to adopt the flood overlay. The whole process highlighted how adopting necessary planning scheme updates on a council-by-council basis is slow, costly, and inefficient.
State government to lead amendments to planning schemes
On 3 October 2025 the Premier announced that the Minister for Planning would lead a streamlined adoption of flood-related planning scheme amendments:
This was backed up up by the Department of Transport and Planning, who also stated that they are developing new risk-based planning and building controls help planners and developers make informed decisions about:
- how to build (using flood-safe construction standards).
- where to build (avoiding the highest-risk zones)
- what to build (designing resilient structures)
Melbourne Water flood mapping
On 4 October 2025 Melbourne Water released their updated stormwater drainage flood map for the City of Yarra.
Flooding isn’t always best managed by adding new drains and retarding basins. The best approach is to understand where floods might occur, so we can raise awareness of flood risk and be better prepared.
Melbourne Water
Our view
Stormwater drainage is an important issue for Streets Alive Yarra because flooding on our streets impacts on how people are able to move around our city, and it affects how streets are designed. The issue of flood mapping isn’t about council’s maintenance of drains, it’s about climate-change induced severe rainfall events that overwhelm even the best-maintained drainage system. Deferring the introduction of an updated flood overlay into Yarra’s planning scheme is contrary to state government policy, and failing to inform property owners of flood risk could expose Council to legal action. Instead, Council should proactively work with the state government to adopt the flood overlay.