Environmental risks
Planning controls have traditionally required councils to carefully assess environmental risks — including flooding, stormwater management, and land contamination — before approving developments.
Under the current reforms, these safeguards are being weakened. New fast-track pathways and legislative changes limit what councils can consider, while accelerating approvals under simplified, standardised rules.
Reduced ability to assess risk
Councils are increasingly constrained in their ability to fully evaluate environmental conditions on a site.
This includes reduced scope to assess:
- Flood risk and drainage capacity
- Land contamination from previous uses
- Cumulative impacts of multiple developments in an area
In some cases, developments may proceed even where risks are known but cannot be fully addressed within the streamlined approval framework.
More hard surfaces, less absorption
Higher-density development typically means:
- Larger building footprints
- More paved areas and driveways
- Less permeable soil and vegetation
This reduces the land’s natural ability to absorb rainfall, increasing stormwater runoff.
The result is:
- Greater pressure on drainage systems
- Higher likelihood of localised flooding
- Increased pollution entering waterways
Strain on ageing infrastructure
Much of Melbourne’s drainage and stormwater infrastructure was not designed for the level of density now being proposed.
Without coordinated upgrades, increased runoff from intensified development can:
- Overload existing systems
- Exacerbate flood risks during heavy rainfall events
- Lead to more frequent and severe local flooding
The reforms do not clearly link increased density with funded infrastructure upgrades, leaving a critical gap in planning.
Climate change intensifies the risk
These changes are occurring at a time when climate change is increasing the frequency and intensity of extreme weather events.
Heavier rainfall, combined with more hard surfaces and limited drainage capacity, creates a compounding effect:
- Flood events become more likely
- Impacts become more severe
- Recovery becomes more costly
Ignoring these factors in planning decisions increases long-term vulnerability.
Impacts on waterways and ecosystems
Increased runoff does not just affect streets and properties — it also impacts natural systems.
Polluted stormwater can:
- Degrade water quality in creeks and rivers
- Damage aquatic habitats
- Disrupt fragile ecosystems
Over time, this contributes to broader environmental decline, particularly in already stressed urban waterways.
Why this matters
Flooding and environmental risks are not theoretical — they have direct consequences for homes, safety, and financial security.
Poorly managed development can lead to:
- Property damage and rising insurance costs
- Health and safety risks for residents
- Long-term environmental degradation
Once development is approved and built, these risks are difficult and expensive to mitigate.
What this means for Melbourne
Without proper assessment and infrastructure planning, increasing density across Melbourne risks amplifying flood and environmental hazards.
Effective planning must integrate growth with environmental constraints and long-term resilience.
The current reforms move in the opposite direction — prioritising speed of approval while reducing the system’s ability to properly manage risk.