Population growth, increasing urbanisation and climate change mean the historical arrangements around flood, drainage and stormwater management established over 90 years ago need to be reviewed in a contemporary setting to enable the institutional arrangements to meet the needs of our growing city and its inhabitants into the future.

Flooding in metropolitan Melbourne has significant economic, social and environmental impacts. Our urban stormwater assets and services play a vital role in helping to recharge groundwater, maximise availability of water for greening and cooling city landscapes and, reduce adverse impacts of stormwater discharges to our waterways.

DELWP, in partnership with Melbourne Water and the 38 councils of the region, is committed to ensuring the management of our urban stormwater assets and services meets the needs of our growing population into the future.

Together with the Municipal Association of Victoria (MAV) and Melbourne Water, DELWP is seeking input from councils and other stakeholders to examine the division of responsibilities for stormwater assets and services.

Fast facts

  • Flooding in metropolitan Melbourne and urban areas across Victoria is a growing problem as we see increased severe storm events and more non-absorbent surfaces.
  • In Melbourne, there are approximately 232,000 properties estimated to be at risk from flooding from the rivers, creeks and drains in Melbourne.
  • In metropolitan Melbourne, many public stormwater and drainage assets are managed under a 60 hectare catchment convention established in 1927.
  • The annual average damage cost of flooding has been estimated by Melbourne Water to be $399 million.

May 2020 update

DELWP, MAV and MW held a joint workshop 13 March 2020 to explore potential options for stormwater management. Participants developed considerations and ideas for future arrangements.

The workshop outcomes will be developed into potential options which will be thoroughly examined and tested with Councils, Melbourne Water and other stakeholders.

Next steps
  • The outputs from the workshop will be collated by the Project Working Group for consideration by the Joint Reference Group.
  • The Joint Reference Group, comprising of representatives from local government, DELWP and Melbourne Water, will consider and refine and short list options for approval by the Project Steering Committee.
  • A multi-criteria analysis will then be done on the prioritised options. The results will be circulated to the 38 councils, Melbourne Water and other stakeholders for consultation and submissions will be sought.
  • Following an engagement process with stakeholders, the Project Steering Committee will provide recommendations to the respective agencies for endorsement
  • Final recommendations will then be presented to the Minister for Water for consideration including any statutory changes that may be proposed

Melbourne Urban Stormwater Review

The responsibilities for agencies today has changed significantly from when the current arrangements were introduced.

Melbourne Water and the 38 councils in the region currently manage different aspects of public stormwater infrastructure and services.

The review of urban stormwater management will help clarify responsibilities between Melbourne Water and local government to ensure our stormwater assets and services:

  • are considered as a water supply resource.
  • support healthy waterways and bay water quality
  • improve green infrastructure, urban cooling and amenity
  • contribute to effective flood mitigation

Over the last two years, DELWP, Melbourne Water and MAV have explored the issues around stormwater and flood-risk management and developed a shared vision. The MAV has also convened a local government working group comprising a cross-section of councils from the Port Phillip and Westernport region.

Initial insights: The 60 hectare convention is no longer working, Upstream/downstream issues and how to be fair, it won't be easy, it is about money so it's important to understand the model, it can't be "one size fits all", legacy issues, clarity on responsibilities, and cooperation is important

A Steering Committee comprising senior representatives from DELWP, Melbourne Water and MAV representing the 38 councils from the region is guiding and leading this review.

This committee will be supported by a project working group and a joint reference group.

The MUSIA Steering Committee has agreed the following scope for the review:

  • Identify current roles and responsibilities for stormwater asset and service provision.
  • Consider the impact of emerging issues such as population growth, climate change, increasing development, urban densification, and water quality.
  • Describe the modern, forward-looking service level that the community should expect from the sector in the context of State integrated water management policy directions.
  • Identify the most efficient means and institutional arrangements to deliver that service level to the community.
  • Assess whether the 60ha catchment threshold continues to be a useful delineation and investigate new options that would best decide roles and responsibilities for stormwater management.
  • Address the most effective way of mandating those responsibilities so that there is clear line of sight from obligation to investment planning to on-ground service delivery.
  • Address arrangements for how the most efficient means of delivery of that service level is funded and articulate a transition plan.

A clear, flexible, adaptable and holistic catchment-based approach where stormwater is managed as part of the complete water cycle to achieve greatest community value.

This Shared Vision has been developed through workshops with participants  from DELWP, Melbourne Water and local government.

The MUSIA Steering Committee has also developed an expectation statement to build on the vision for stormwater management toward 2050.


Urban stormwater is recognised as a resource that can be used and managed to support a healthy environment, prosperous economy and thriving communities. By managing stormwater services holistically this will provide best practice flood and drainage management, stormwater quality treatment and flow management, water harvesting and irrigation, and urban greening and cooling.

The costs and benefits of interventions are transparent and clearly allocated to the institutions that can most efficiently manage them. Communities in the region are effective participants in the cost vs service level choices and are confident in the government’s ability to manage stormwater effectively. The development industry enjoys a seamless experience when engaging with agencies as they plan, explore and incorporate new innovative approaches to water, and liveability features in the suburbs of the future.


The 60.7 ha catchment boundary is a convention resolved in 1927 by the Melbourne and Metropolitan Board of Works (MMBW), which delineates the Melbourne Water and local council drainage management responsibilities, with some exception. The original resolution defined main drains, now regional drains, as any ‘drain, creek or watercourse with an area greater than 150 acres [60.7 hectares], and greater than 800 feet [243.8 metres]’ to be designed, constructed and managed by the MMBW (now Melbourne Water). Any small catchments are the responsibility of local councils.

The development of the Victorian Floodplain Management Strategy identified that Melbourne Water and many councils wanted the 60ha convention reviewed and roles clarified.

The current institutional arrangements are based on a 90-year-old convention that was introduced when very different approaches to drainage of stormwater were practiced, and the urban landscape was considerably smaller than now.  

These emerging challenges require new ways to meet the needs of communities now and into the future.

Urban flooding is a significant issue with potential to increase in metropolitan Melbourne.

More severe storm events and increased urbanisation result in higher flows of stormwater over non-permeable surfaces. This causes greater levels of pollution and erosion of waterways and increased risks of flooding.

Urban flooding has the potential to incur significant economic, social and environmental costs.

Frequent flooding is defined as flooding that has a 20% Annual Exceedance Probability (AEP) of occurring in any given year (1 in 5 year Average Recurrence Interval or ARI).

Frequent flooding can be mitigated by effective management of stormwater infrastructure. This is likely to decrease damages and particularly disruption from stormwater flooding.

In Melbourne, there are approximately 232,000 properties estimated to be at risk from flooding from the rivers, creeks and drains in Melbourne.

The annual average damage cost of flooding has been estimated by Melbourne Water to be $399 million. Up to 60% of this may be associated with local drains.

Flood, drainage and other water management assets continue to grow along with urban development. Appropriate management and design of new and existing flood, drainage and other water management assets is critical to managing the pressure of increasing stormwater volumes and, serving the growing city well.

Melbourne Water collects fees through a waterways and drainage charge levied on all properties across the region. Councils collect funding through local rates.

Enabling future funding and locally appropriate service decisions are an important consideration for this project.

Clarifying responsibilities for urban stormwater management will support future collaboration to deliver more integrated water projects and services.

Integrated water management may provide opportunities to achieve additional benefits beyond flood and drainage. This includes water harvesting and recycling for irrigation and other non-potable purposes.

To be effective, integrated water management requires collaboration between government agencies, industry and communities to plan land-use, water-use and combined storage and drainage to reduce stormwater peak and runoff volume.

    The review aims to achieve several objectives.

  • Considering and responding to the contemporary drivers for managing stormwater more strategically including integrated water management, flood risk mitigation.
  • Describing a modern and forward-looking service level that the community can expect from the sector.
  • Adapting and clarifying the rules to better meet the current and emerging challenges Melbourne Water and councils are managing including population growth, climate change, increasing urban densification, and decreasing water quality.
  • Identifying the responsibility of assets and services that are delineated by collecting stormwater from a catchment larger or smaller than 60 hectares, known as the 60-ha convention.
  • Adopting the most efficient, catchment wide arrangements to deliver on the modern service level expectations and the policy direction of Integrated Water Management.
  • Ensuring the arrangements reflect the growing size of the assets under management by Melbourne Water and local government, and that it is legislated so there is clear line of sight from obligation to investment planning to on-ground service delivery.

The review only includes the management of assets and services in the public realm. Private property management is out of scope.

The 60ha threshold will be reviewed to determine optimal responsibilities, and processes, and to enable decisions best for catchments between state and local government agencies.

The project will agree on functions and associated roles and responsibilities for strategic and risk planning (including mapping). This will also include the development, management, maintenance and monitoring of urban stormwater management assets.

This project will consider and, where possible, inform and align with related plans and regulations in development. It will not dictate or require specific outcomes from those processes.

The review started in mid-2017. The first phase involved issues identification and developing a shared vision by the Department of Environment, Land, Water and Planning, Melbourne Water, the Municipal Association of Victoria and other stakeholders.

The next phase has commenced. This phase will progressively identify potential options and models for reform through 2020.

The review only includes the management of assets and services in the public realm. Private property management is out of scope.

Communities will benefit from greater clarity in which government entities are responsible for different assets and services. They will also experience greater clarity on the minimum levels of service they can expect.

Updates will be provided and there will be opportunities for local councils to participate in interviews, attend options workshop, provide nominate for a joint reference group that will be established by the Department of Environment, Land, Water and Planning (DELWP), provide feedback to an options paper and participate information sessions and training following approval of the final decision. Municipal Association of Victoria (MAV) will keep council CEOs informed as the project progresses.

Updates will be provided by DELWP, MAV and Melbourne Water through their respective networks.

Councils can access MAV updates by visiting the MAV Members Website.

Project timeline: Overview

Phase 1A: Establishment (complete)

Identification of key project partners and participants. Establishing meetings and agreements in place.

Phase 1B: Scoping (complete)

Consulting with project partners to redefine project scope, vision and explore broad issues. Development of a shared vision paper outlining the structures needed for Melbourne to remain safe and water efficient in 2050.

Phase 2: Identifying potential models (commenced)

Engagement on the operational issues and details required to support identification of preferred approaches. Options paper developed detailing how potential models would work to support the shared vision.

Phase 3: Options Analysis (to commence mid- 2020)

Shortlist and analyse potential models for institutional arrangements following stakeholder input.

Phase 4: Consultation (to commence late 2020)

Circulate draft recommendations for final stakeholder consultation.

Phase 5: Plan implementation (early 2021 - mid 2021)

Draft implementation plan and assign responsibilities based on draft recommendations.

Phase 6: Organisational sign-off (mid 2021)

Present draft implementation plan for organisational sign-off.

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Page last updated: 03/06/20