Return to News

Changes to NSW dam regulation – what you need to know

Atc News Dam Bobadil

ATC Williams works closely with the NSW Dams Safety Committee and has a clear understanding of the expectations for dam performance and safety across the region. We outline the recent changes that affect dam engineering in NSW and what they mean for you.

How are dams regulated in NSW?

Dam Safety NSW is responsible for “regulating the safety of dams in NSW.” The Dam Safety Act 2015 supersedes the previous 1978 Act. Under the new Act, legislative guidance is provided by the Dams Safety Regulation 2019 (source: Dam safety reform, summary of legislation changes), and replaces previous guidance sheets.

The new legislation reflects a recognition by Dams Safety NSW of the changing standards and practice applied to dams, with emphasis on safety and accountability for the public and the environment. The stated intent of the change is:

  • “to improve the safety management practices of declared dam owners
  • to improve the regulator’s ability to enforce the requirements
  • to remove the potential conflict of interest resulting from dam owners being on the board of the Dams Safety Committee”.

What are the significant changes?

Changes in the legislation relevant to dam owners and designers are:

  • The term “Prescribed Dams”, as we have become accustomed to in the past, has changed to “Declared Dams”. A dam will become “Declared” if as a result of failure, human life would be endangered, or the severity of loss or damage would be major or catastrophic.

  • The approval of a dam design previously provided by the Dams Safety Committee is no longer required. However, the dam design must be carried out under an AS/NZS ISO 9001:2016 quality management system, which means that accountability for the performance of the dam will now rest with the designer.

  • Notwithstanding the above, engineering controls on the design and performance of Declared Dams will be maintained by an independent review of:
    • Consequence Category assessments
    • Design for all High and Extreme Consequence Category dams
    • Safety reviews (required nominally every 15 years)

  • All dams require Operations and Maintenance Plans. For High and Extreme category dams, plans must be updated annually, and for other Declared Dams, every five years.

  • An Annual Report, addressing compliance with dam safety standards, will replace the former Surveillance Reporting requirement.

  • All dam owners must implement a Dam Safety Management System (DSMS) that defines a risk-based approach to managing the dam. It is of interest that once a Declared Dam falls below a defined safety threshold, risk-based decisions are based on “so far as is reasonably practical” (SFAIRP) principles. This safety threshold is benchmarked against ANCOLD standards.

The new Act and Regulation came into effect on 1 November 2019, with standards and guidelines progressively being developed.

Important dates to know…

  • There is a two-year transition period to fully implement the legislation (ending on 1 November 2021).

  • For dam owners “who do not have operations and maintenance plans, or emergency plans for their Declared Dams”, Dam Safety NSW required this documentation to be submitted by 1 May 2020.

Please refer to for further advice.

Guidance on HRA submissions

Did you know the NSW Resources Regulator now requires HRA (High Risk Activity) submissions for dam developments on all mine sites? It is notable that tailings storage facilities (TSFs) for all operations other than coal, opal and small gemstone mines, are now considered as HRAs. The specific activities considered to be High Risk include:

  • Establishment
  • Operation
  • Alteration
  • Decommissioning

You can read more about HRAs at

How is ATC Williams assisting dam engineering?

ATC Williams has worked within the NSW mining industry for more than 25 years, through the coalfields and metalliferous mining regions. We are committed to maintaining this relationship well into the future, supported by the recent opening of our Singleton office.

Dam engineering is a significant component of our business, both in the tailings and mine water management space. We are well prepared to transition with the new legislation and offer the full range of services related to dams, from siting, geotechnical investigation, design, construction support, operational planning, and closure. We can also assist in the preparation of HRA submissions for your TSF.

To understand how these changes may affect your operation, please contact:
John Milson, Principal Engineer and Hunter Valley Office Manager,
Genevieve New, Senior Associate Melbourne or your existing ATC Williams contact.

Atc News Dam Rosebery