Guidelines on Dam Safety Management (2003)
These dam safety guidelines are intended to apply to what might be termed conventional dams (eg. for water supply, irrigation, power and flood mitigation). Guidelines for dam safety management of tailings dams are published separately.
These guidelines have been developed by ANCOLD with the aim of promoting appropriate dam safety management practices in Australia. It is recognised that circumstances vary enormously from dam to dam and different administrative frameworks apply in each state. Some states have specific dam legislation while other rely on more general provisions. For these reasons, ANCOLD puts this guideline forward as an advisory document that must be interpreted by appropriately qualified and experienced professionals in each case. In no sense is it intended that they should be regarded as a standard.
The guidelines will again be reviewed when knowledge and practice have developed to the point where an upgrade is required. With this in mind, comment from users and others is welcomed.
This document has been prepared as a companion to the 2001 ANCOLD Guidelines on the Environmental Management of Dams. Since the 2001 guidelines were published much has been learnt about the critical issues that drive environmental concerns for both dam practitioners and the broader community arising from the construction of new dams, dam upgrades or altered operational strategies. The objective of this companion volume to the 2001 Environmental Guideline is to increase environmental awareness by encouraging more sustainable planning, design, construction and operation inputs to large dams. As such this companion volume complements rather than replaces the existing 2001 guideline. This companion volume focuses on:
Describing the complex Commonwealth and individual State regulatory environments that must be dealt with in all dam projects;
Discussing key issues surrounding the practices for effective stakeholder and community consultation;
Considering risk assessment for environmental matters associated directly with construction and operation, as well as the broader and more complex regulatory concerns of cumulative and consequential impacts; and
Providing a series of technical Practice Notes on a range of environmental issues that dam owners/ operators need to be aware of in all dam projects
A series of Practice Notes has been presented in Part B setting out a brief overview of current knowledge on a range of technical and operational matters of interest to dam owners/operators. These are not exhaustive reviews of current knowledge but rather serve to raise a level of awareness on a range of issues that need to be considered at the various stages of planning, constructing, operating and decommissioning a storage with respect to environmental concerns.
The 2014 Guidelines are intended to be regularly updated to reflect the changing regulatory environment as well as increasing technical knowledge about environmental management.
The two guidelines should be regarded as companion volumes for reference, with the 2014 Guidelines providing a targeted and practical environmental perspective.
The Technical Working Group set out to make these Guidelines simple and straightforward, avoiding scientific and technical jargon so as to appeal to the broader audience it targets. I take this opportunity to thank the members of the working group for their efforts in bringing this document to fruition.
The Guidelines are not a ‘rule book’ but rather a document to raise awareness of significant environmental matters to be considered by all dam owners/operators. ANCOLD welcomes comments on these Guidelines for inclusion in future editions.Learn more
Within about ten years of the 1991 edition of the ANCOLD Guidelines on Design Criteria for Concrete Gravity Dams being published the Limit State design approach it proposed fell out of favour with Australian dam engineers. The ANCOLD Executive recognised this situation and resolved that the Guidelines be revised to reflect the preferred design approach amongst Australian dam engineers. A Working Group and a separate Expert Review Panel were formed in 2005 to review the Guidelines with the intention of preparing a document that was not only more in line with the current thinking but would also be widely adopted and used by practicing dam engineers.
It has not been an easy task for the Working Group and the Expert Review Panel. Although the working stress method, with associated Factors of Safety, approach was agreed amongst the team, it took considerable time and effort to reach consensus on the details, in particular chapters four through to six. The issue that took most effort to resolve was how the Factors of Safety relate to the level of certainty of the inputs, including knowledge of the foundations, loads, strength of materials and assumed mechanically feasible failure surfaces. The notes to Table 6.4.1 and the discussion in Appendix A highlight this issue.
One thing the drafting team agreed on early, and unanimously, was the importance of the concrete gravity dam design team having a thorough understanding of the foundation conditions, the development of a detailed geological model of the foundations and an understanding of the kinematically feasible failure mechanisms. In keeping with this principle, this revision of the guidelines has the section on foundations at the front of the document. There is a strong recommendation that the design team has expertise covering foundation geology and rock mechanics as well as the dam engineer.
These Guidelines provide a basis for design of concrete gravity dams in most situations. However, they require that the user will be a professional dam engineer with significant experience who is able to use sound engineering judgement in the application of the guidelines. It is recommended that less experienced dam engineers using these guidelines do so under the advice and guidance of an experienced dam engineer. It is the dam engineer who is responsible for the design.
On behalf of ANCOLD I would like to thank the members of the working group and all the other contributors that persevered in developing and bringing these Guidelines to fruition. They will be of great assistance to dam engineering professionals both within Australia and internationally.Ian Landon-Jones Chairman, ANCOLD Learn more
The ANCOLD Guideline brings together improved appraisals of the earthquake loadings that a dam may suffer and then describes appropriate methods for analysis and evaluation. Whilst specific to the Australian considerations the majority of this guideline could be applied to dam structures throughout the world. The ICOLD Bulletins No 46. (1983), No 62. (1988) and No 72. (1989) are parallel documents in this regard, although not including recent advances.
This guideline is not a design code, and dam designers must continue to apply their own considerations, judgements and professional skills when designing dams to resist earthquakes. As time goes on there will no doubt be improved data and design tools to help the designer and it is intended that this guideline will be updated as circumstances dictate. ANCOLD welcomes contributions to discussion on this guideline which will assist with future revisions.Learn more
In Australia we have a very diverse portfolio of dams, some regarded as being designed and constructed before there was a good understanding of the loading conditions that could apply. Sometimes there is limited knowledge of the actual details of construction and always there is a desire to ensure that the community’s resources are properly applied. The difficulty facing those who allocate funds for the benefit of the community measure the cost against the benefit achieved and to compare that with opportunities available.
Risk Assessment gives us the tools to estimate the likelihood of a circumstance occurring and of its consequences. It also gives us the tools to estimate what these will be after any improvement. These tools are diverse and can be imprecise. As time goes on our methods will improve but chance and circumstance will always be with us. But, if we use consistent methods, we will generally be able to rank the possible outcomes and compare them, in scale, with others.
ANCOLD is aware of the diversity of dams and the circumstance associated with them and offers this document merely as an indicator of the approach that may be taken. Nevertheless we hope that its adoption will lead to greater comparability between individual workers.Learn more