Devastated home owners are demanding answers after about 900 properties in an inner-city estate were suddenly designated as being at risk of flooding in an update to modelling by Melbourne Water.
The Kensington Banks estate, east of the Maribyrnong River, was completed about 25 years ago in a joint partnership between the state government, the City of Melbourne and former development business Urban Pacific.
Richard Reilly’s home is one of 900 Kensington Banks properties now deemed at risk of flooding.Credit: Jason South
The estate won several awards as a successful urban renewal project that transformed a former abattoir and flood-prone area through extensive mitigation works to prevent inundation of about 1000 new townhouses and apartments.
Now, almost every home in the estate is being labelled as flood-prone after Melbourne Water revised its 2003 modelling for the Maribyrnong River catchment, which has left thousands of residents facing surging house insurance costs and plummeting property values.
Richard Reilly, who bought his Kensington Banks home in 1999, was shocked by the new map given the flood mitigation works.
“It’s confronting, quite frankly. This new map overlay seems quite extreme,” he said.
The new maps were produced by Melbourne Water after the Maribyrnong River flooded in October 2022 and inundated about 600 properties, mostly in the suburb of Maribyrnong.
While the maps show marginal changes in the flood threat for most parts of the catchment in 2024 and 2100, only Kensington Banks – which is immediately downstream of Flemington Racecourse – has such a drastic change in risk should a one-in-100-year flood hit in 2024.
In the 2022 flood, which was considered a one-in-50-year event, Kensington homes escaped damage but 10 businesses, two apartment block basements and many cars were inundated.
Reilly, whose yearly cost to insure his property against flood has increased from $180 to $5000, remembers seeing the water creep up higher than he had ever seen and reach the second bluestone step of his elevated townhouse.
He was among the community members who opposed Flemington Racecourse’s controversial 1.6-kilometre flood wall before it was built in 2007 and said he wanted information about its impact on Kensington homes.
“How much difference will the racecourse wall make to the height of a potential flood going forward is a key question we want answered,” he said.
MP David Ettershank lives in Kensington and is on the committee of the flood parliamentary inquiry, which was established after Melbourne Water’s own flood review came under fire for its narrow scope and perceived lack of independence.
The Legalise Cannabis MP said he was horrified by the new flood modelling for Kensington and said the neighbourhood’s residents, who had relied on existing flood maps, were devastated.
Kensington Banks photographed this month.Credit: Jason South
“We’re not talking about Maribyrnong township with 100-year-old houses. These are places where houses are about 20 years old and supposedly built above the flood level,” Ettershank said.
“They all bought being told they’re on this elevated land that’s protected from flooding. Now those people who have invested their life savings in their property are confronted with a whole different proposition.”
Ettershank said it was critical to understand why the flood map had changed so dramatically over Kensington Banks and what the effect of the racecourse wall would be on the area in a one-in-100-year event, which is the benchmark used for flood planning.
Analysis made public by Melbourne Water assesses how the wall affects properties on the river only in a one-in-50-year flood.
It found that the wall increased water levels by six centimetres in industrial parts of Kensington in 2022.
Ettershank said it was not clear how residential parts would be affected in a more severe flood.
“Asking questions of Melbourne Water is a bit like wrestling with a column of smoke,” he said.
At last week’s parliamentary hearing, the independent chair of Melbourne Water’s flood review, former judge Tony Pagone, said he was concerned that the only modelling was based on a one-in-50-year flood.
“It concerned me because you wonder what would happen if you had a [one-in-100-year] event?” Pagone said.
In a separate hearing, Melbourne Water executive Tim Wood said his team was yet to fully examine the impact of the wall in a one-in-100-year flood, but that a “high-level initial assessment” was that it had no impact on Kensington Banks.
Hydrologist Geoff Crapper, who worked at Melbourne Water until 2003 and now advises the Maribyrnong Community Recovery Association, said the lack of public detail around the racecourse wall’s effects in a one-in-a-100-year flood was an “obvious deficiency in the flood review’s terms of reference”.
The Victoria Racing Club has repeatedly said it would work with relevant authorities and that its flood wall and compensatory works were built in accordance with approvals granted by the state government and Melbourne Water.
The wall has been a flashpoint ever since it was approved in 2004 by Labor’s then planning minister, Mary Delahunty, despite opposition from three local councils.
A Melbourne Water spokesman said the new flood maps were influenced by factors including climate change, urban development and new technology that used millions of data points to ensure a result that was of much higher quality than before.
The maps will be used to update flood overlays in municipal planning schemes, inform emergency management and investigate new potential works to prevent flooding.
“These new models give us the information we need to best prepare our communities for this risk,” the spokesman said.
The Flemington Racecourse flood wall kept the track in perfect condition while streets and properties flooded nearby in 2022.Credit: Emma Johnston
Melbourne Water has not publicly revealed projected flood depths for Kensington. Home owners are instead being asked to call the water authority to receive individual information. Its spokesman said some properties would experience only small amounts of water in their backyard.
The spokesman said the mitigation works for Kensington Banks, which include a levee and retarding basin, were designed on the conditions and best information available.
“Flood technology was much less sophisticated in the 1990s,” he said.
“These mitigation measures continue to provide good protection for the community of Kensington Banks but do not fully protect these properties in the current and 2100 one-in-100-year events.”
Steven Papadopoulos, the chief executive of Urban Pacific when Kensington Banks was being developed, said government flood experts meticulously analysed plans for the project based on the available evidence.
“The question of government is what, if any, more work could have been done at the time? But it’s a Harry Hindsight question,” he said.
A spokeswoman for Water Minister Harriet Shing said decisions made for Kensington Banks would have been based on the best information at the time.
Victorian MP and Kensington resident David Ettershank.Credit: Simon Schluter
“Melbourne Water has updated its modelling because climate change was causing more severe and frequent flooding events,” the spokeswoman said.
Victorian Greens leader Ellen Sandell, a resident of Kensington Banks for 15 years, said she was shocked to discover the government information she had trusted when buying her home was now wrong.
She was critical of the communication with the release of the new maps, which were published on Melbourne Water’s website in late April.
Some residents say they began receiving leaflets alerting them to a general change in flood maps late last week, while others have not received anything in their letterboxes.
Melbourne Water and City of Melbourne spokespeople said the release of the flood maps was communicated via letterbox drops, and information sessions have been organised.
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