Melbourne Water Releases Draft Stormwater Flood Maps for Banyule and Moonee Valley, Flagging Over 19,000 Properties

New Flood Maps Show Thousands of Properties at Risk in Melbourne's North-West

Melbourne Water has released draft stormwater flood maps for the municipalities of Banyule and Moonee Valley, identifying thousands of properties at risk during a severe storm. The maps, published on June 18, 2026, model flooding during a 'significant rainfall event'—specifically, one with a 1% annual probability of occurrence (a "1-in-100-year" event).

In Banyule, approximately 7,400 properties are identified as at risk, including areas in Heidelberg, Ivanhoe, and Rosanna.
In Moonee Valley, around 11,730 properties are flagged as at risk, covering suburbs like Essendon, Moonee Ponds, and Ascot Vale.

The maps use a hazard rating system ranging from H1 (lowest, representing shallow flooding) to H6 (highest, indicating deep, fast-moving water). The distribution of risk varies significantly between the two municipalities:

• Banyule: Of the affected properties, 44% are rated H1 or H2 (shallow, lower-risk flooding).
• Moonee Valley: A much larger proportion—81% of affected properties—fall into the H1 or H2 categories. However, 7% are rated H4 or higher, indicating a more serious threat.

These maps are part of Melbourne Water's comprehensive two-year plan to update flood models for all 38 metropolitan municipalities, replacing older data. This initiative has already flagged significant risks elsewhere:

• In October 2025, over 60,000 properties in Darebin and Yarra were identified as flood-prone.
• Similarly, 32,000 properties in Glen Eira and Merri-bek were highlighted in the same period.

"The online maps provide clear information for residents to check their flood risk," said Chris Brace, Melbourne Water's executive general manager.

Residents can access the draft maps via an online interactive tool. A public community consultation period is now open and will run until August 12, 2026. It is important to note that no planning controls have been changed as a result of these draft maps.