Rising flood risks and extra housing has Knox Council asking for help to cover $74.4 million drain renewal

The council’s stormwater network is currently sized to provide protection against one-in-five-year flooding events in residential areas and one-in-10-year events in industrial areas.

Matthew Sims
December 09, 2025

Knox Council has reached out for a helping hand from the state and federal governments to improve its stormwater management infrastructure, as flooding risk increases and 43,000 more houses are set to be built by 2051.

❓What’s happened: Knox Council passed a motion on Monday December 8 to write to state and federal MPs requesting “adequate funding” to deliver better flood resilience infrastructure in flood-prone areas in Knox.

Under the council’s Stormwater Asset Management Plan for the next 10 years, work would focus on upgrading undersized and old assets impacted by climate change.

💰 How much would this cost? The estimated cost to replace all of the council’s grey stormwater assets – including more than 1,150 kilometres of pipes and 39,673 drainage pits – would be about $292 million.

According to the council’s plan, it would spend $74.4 million on stormwater assets over the next 10 years, including $42.9 million to renew damaged infrastructure and $4.8 million to improve capacity or create new systems.

“Significant downpours” on the rise: How can the Yarra Ranges prepare for increased flash flooding?

The Yarra Ranges has a long history of extreme rainfall events, including in February 2011, October 2010, September 2010 and February 2005.

💧 Why is flooding becoming more frequent? According to the State Government’s 2024 Climate Science Report, with each degree the Earth warms, the atmosphere can hold about seven percent more water vapour, leading to more moisture in the air and higher intensity rainfall events.

Environment Victoria reports global warming – and humanity’s dependence on fossil fuels – directly causes this extra water to be created and stored.

As extreme weather events become more frequent, the existing infrastructure of much of our community will need to be upgraded. Knox is just one example of a local council no longer best designed to cope with an event like flash flooding.

“Another hurdle”: How will Yarra Ranges’ proposed erosion overlays impact the housing market?

“It cuts down the appetite to live in these high-risk areas."

⛈️ Systems under stress: Knox councillor Meagan Baker said support was needed to ensure the council could help deliver the state government’s request of 43,000 additional houses by 2051.

“These challenges are real, the growth is forecasted and the action is necessary,” said Baker.
As a volunteer firefighter, Knox councillor Robert Williams said he had seen first-hand “the increase of floods through Knox”.