Flooding
- Waterways and drainage system
- Flash flooding
- Stormwater management measures
- Properties affected by flooding
- New floods interactive explorer
- Be prepared for floods
- Planning scheme amendments
Waterways and drainage system
Melbourne Water has a program in place to regularly monitor the condition of the waterways and drainage system to ensure it remains in good condition and continues to provide essential flood protection.
Around $16 million a year is invested in drainage inspections, maintenance and flood protection projects and in recent years we have made significant progress in upgrading Melbourne’s drainage system.
The drainage system copes well with most storms experienced across Melbourne. However, from time to time, storms can occur of such intensity that not all the stormwater can get into the drains at once and flooding occurs.
Flash floods
Flash floods happen when a large amount of rain falls in a localised area over a very short period of time. These localised storms are generally beyond the capacity of any drain, and it would not be economically feasible to design drains to cater for these very large, but infrequent storms.
After flooding, we inspect our drains to ensure they were working to full capacity and to see what impact these extreme storms have on our drainage system.
It is important to keep the drainage system clear of litter and debris to avoid blocked drains that can cause flooding. This is also necessary to protect and improve the health of Melbourne’s rivers, creeks and bays.
Stormwater management measures
Today, new developments and redevelopments incorporate stormwater management measures that provide greater flood protection. About 150 areas known as retarding basins are used to help prevent flooding around Melbourne. They slow the flow of stormwater being carried in the drainage system by storing it for a period of time. Retarding basins often double as parks and playing fields.
In addition, we have surveyed 600 kilometres of underground drains and the information is being incorporated into council planning schemes to ensure that the community is aware of flooding risks, and to promote appropriate development.
Properties affected by flooding
Under arrangement with Melbourne Water the retail water companies and other authorised agencies can help you determine whether a property is likely to be affected by flooding.
Planning permit applications to develop on flood-prone land are referred to Melbourne Water from local councils. We assess applications on the basis of what impact a major flood would have on the development, and specify requirements to ensure new developments are protected from flooding.
For more information about insuring your home or business against flood damage, please contact the Insurance Council of Australia.
Floods Interactive Explorer
Storms can cause severe localised flash flooding. Through Melbourne Water’s animated Floods Explorer, students and the community can explore what happens when it rains in urban areas, how houses and parks are affected, and the consequences of blocked gutters and stormwater pollution. Discover the inside story about how councils, the Bureau of Meteorology, the SES and Melbourne Water work together on planning and responding to floods.
Be prepared for floods
Emergency Management Australia's booklet What to do before, during and after a flood (PDF 865 kb) contains useful information on how to prepare for and minimise the effects of flooding.
Planning scheme amendments
Melbourne Water is constantly reviewing flooding information for the wider Melbourne area. We provide this information to Councils, so that they have accurate information about land within their municipality that may be affected by flooding during severe storms.
Councils use this information in their local Planning Schemes to create a Special Building Overlay, Land Subject to Inundation Overlay or Floodway Overlay.
Each Council's planning scheme sets out policies and provisions for the use, development and protection of land within their municipality. Overlays are shown as maps in the planning scheme, which identify an area for which a particular planning control is needed.
Special Building Overlays are planning controls that apply to land affected when a severe storm exceeds the capacity of an underground drain. Planning permits are required for any buildings and works within the overlay areas.
Land Subject to Inundation Overlays are planning controls that apply to land affected by inundation associated with waterways and open drainage systems. These areas are commonly known as floodplains. A planning permit is required for any buildings and works within the overlay area.
Floodway Overlays are planning controls that apply to land which is identified as carrying active flood flows associated with waterways and open drainage systems. This overlay is used for areas where the depth of flooding would be in excess of one metre. A planning permit is required for any buildings and works within the overlay area.
Updating boundaries for overlays
From time to time, the boundaries of these overlays need to be updated if improved drainage information is made available.
Updates to the overlay boundaries ensure drainage issues are addressed at the outset of any development process and that proposals are designed accordingly.
Changes to the overlay boundaries are done through a Planning Scheme Amendment.
Current amendments to planning schemes
- Mornington Peninsula Scheme Amendment C105 - Comments are invited on this amendment.
More information:
Downloads
You will need Adobe Acrobat to access the above PDF documents. 