A dam is a barrier or structure built across a waterway to obstruct and control the flow. Dams vary in size from small earth embankments, often for farm use, to large concrete structures. Dams Safety NSW regards the following structures as dams:
- dams
- weirs
- off-river storages
- retarding basins
- tailings dams.
You can read more about defining dams for declaration and a list of structures that Dams Safety NSW does and does not consider to be dams.
Dams are built for various reasons, including:
- water supply
- irrigation
- hydro-electricity
- flood control (eg retarding basins)
- environmental controls (eg tailings storage facilities that impound their contents).
NSW is home to tens of thousands of dams, from small farm dams to major dams like Sydney’s Warragamba Dam.
Risks to dam safety
The principles and requirements of dams safety legislation help declared dam owners manage the risk of dam failure. Although a particular structure may not be a dam for declaration purposes, all dam owners have a responsibility to the community to address any failure risk. If you own a structure that could endanger life if it fails and releases its contents, consider using the principles in the dams safety legislation to manage that risk.
Declared dams
Dams Safety NSW ‘declares’ dams that can potentially endanger life downstream, cause major damage or loss to infrastructure, the environment or have major health and social impacts. Each dam is given a consequence category that reflects this potential.
According to Part 2 Section 4 of the Dams Safety Regulation 2019 this includes:
- a dam with a wall that is more than 15 metres high
- an existing or proposed dam that Dams Safety NSW is reasonably satisfied would endanger the life of a person, or result in a major or catastrophic level of severity of damage or loss if it failed
- dams that were ‘prescribed’ under the old Dams Safety Act (1978) became declared dams under the new Act.
Once a dam is declared by Dams Safety NSW, the dam owner must comply with dams safety legislation.
Interactive map of NSW declared dams
The Dams Safety NSW interactive map allows you to see the exact location of all declared dams across NSW. The map features 12 different of spatial layers and allows you to filter declared dams according to local government areas, suburbs, dam owner and dam name.
Declared dams shown on the map are current as of June 2023 and are subject to change as dams are declared and de-declared.
Should your dam be declared?
If people would be at risk if your dam failed, it needs to be referred to Dams Safety NSW to be considered for declaration, even if it is only a small dam or retarding basin.
It should also be referred if dam failure would cause a major or catastrophic level of environmental or economic asset damage or loss. The Declared dams consequence category assessment and determination methodology describes what a major or catastrophic damage or loss refers to in Tables 3A, 3B and 3C.
All dams that are more than 15 metres high must also be referred to Dams Safety NSW to be considered for declaration.
If you think these factors may apply to your dam, contact us to discuss the next steps. Our engineers will assess whether your dam meets the criteria to be declared. They may need you to carry out a preliminary assessment of the dam.
Read more about when and how to ask Dams Safety NSW to declare, or remove the declaration, for your dam.
Revoking a dam declaration
If you believe your dam no longer meets the requirements to be declared and you want Dams Safety NSW to consider revoking the declaration of your dam, contact us.
List of declared dams in NSW
Current list of declared dams in the NSW as of 19 January 2024.