All farm dam owners are legally responsible for the safety of their dams and any death, injury or damage they cause if they fail.
Even if someone else is responsible for your dam failure, you are still very likely to be liable for expenses – which are often more than the original cost of building the dam.
You should regularly inspect and maintain your dams to keep them in good order, and check you have the right licences to build or operate them. If you live in a rural residential area, you may also need to register your dam with your local water corporation.
Dam licences ensure dam owners take proper precautions to protect life and property. Under the Water Act 1989, you need a licence to build, operate, alter or decommission dams on waterways or dams that are considered hazardous in size.
Operating licences for large dams
You must obtain an operating licence if you:
own a dam on a waterway
own a large dam off a waterway that is potentially hazardous
Potentially hazardous dams include those that have a:
wall height of 5 metres or more and a capacity of 50 megalitres or more
wall height of 10 metres or more and a capacity of 20 megalitres or more
wall height of 15 metres or more regardless of capacity
Such dams require surveillance plans, and must usually be regularly inspected by a qualified engineer. You must also have an emergency management plan in case your dam fails or has any other structural fault.
You must pay an annual fee for your operating licence.
Construction licences for building new dams
If you are thinking about building a new dam you should contact Melbourne Water and your local council for advice, as you may need a construction licence and/or a council planning permit.
Generally you do not need our permission to build a dam that is not on a waterway/floodplain and is:
used only for domestic and stock purposes
filled exclusively from roof runoff
However, you should seek advice to build any dam for irrigation or commercial purposes and you must obtain a construction licence for building any:
dam on a waterway
large dam off a waterway that are potentially hazardous
Construction licences usually need a suitably qualified engineer to design the dam and supervise its construction. They also usually require flow bypass arrangements that allow water to pass through or around the dam outside of any authorised filling period.
We generally do not support building new on-waterway dams because they harm the waterway environment and downstream flows. We will only consider them for minor tributaries where there is no alternative site, and where an environmental impact study determines there will not be adverse impacts.
‘Take and use’ licences for dams
A ‘take and use’ licence is needed for all dams used for irrigation or commercial purposes, regardless of their location or size.
You should obtain the water licence before building a new dam, as your licence conditions may need your dam to include particular works to be incorporated into the dams construction.
Further information and application forms
Under the Water Act 1989, if you are applying for a construction or ‘take and use’ licence you may need to:
notify adjoining landholders in writing of your application
advertise in your local newspaper – for applications greater than 20 megalitres
For more information on advertising requirements, as well as sample notification letters, read our advertising guidelines.