A referable dam is one that would, in the event of failure, put a population of 2 or more people at risk. Whether a dam poses a potential risk to population is determined by having the dam failure impact assessed. A dam that is assigned a Category 1 or Category 2 failure impact rating as a result of an assessment is classified as 'referable' under the provisions of the Water Supply (Safety and Reliability) Act 2008 and the Water Act 2000.
Dams that have been assessed as having a Category 1 failure impact rating and non-referable dams that exceed the size criteria (requiring them to be failure impact assessed) must be re-assessed at intervals of no less than five years as set by the chief executive of the department.
A dam satisfies the size criteria if it is:
- more than 10 metres high and has a storage capacity of more than 1500 megalitres; or
- more than 10 metres high and has a storage capacity of more than 750 megalitres and a catchment area more than three times its maximum surface area at full supply level.
A failure impact assessment will also need to be carried out if the owner of a non-referable dam
- proposes to carry out works that will mean the dam meets the above size criteria or
- which meets the above criteria, increases the storage capacity of the dam by more than 10 per cent.
If a dam is assessed as not having a population at risk, it is not subject to the referable dam provisions of the Water Supply (Safety and Reliability) Act 2008.
In addition, the owner of a referable dam who proposes to carry out works that will increase the storage capacity of the dam by more than 10 per cent must also have the dam failure impact assessed.
Under the Sustainable Planning Act 2009 a development permit is required for all new referable dams and for all modifications to existing referable dams which will increase the storage capacity by more than 10 per cent.
Development permit applications must be made on forms prepared and submitted in accordance with the requirements of the IDAS (Integrated Development Assessment System) process of the Sustainable Planning Act 2009.
Dams deemed by Regulation
Sections 1067 and 1068 of the Water Act 2000 provide for the setting of failure impact ratings for existing licenced and unlicenced dams by Regulation.
Under these provisions, the Water Regulation 2002 (PDF)* was used to set the failure impact ratings for 46 existing dams.
See Schedule 12 (p.190) for a list of these dams, and their ownership and location details.
- IDAS referable dam forms for development applications for constructing referable dams
- Referable dams guidelines
- Dam safety authorised officers factsheet: (PDF, 73K)* details their functions, powers and responsibilities
- Australian National Committee on Large Dams Incorporated (ANCOLD) for access to industry guidelines and other dam information
- Department of Community Safety
* Requires Adobe Reader
Last updated 22 January 2013