Gary Hargraves, Russ McConnell and John Ruffini
The acceptance of the use of generalised methods for estimating extreme rainfall has resulted in a growth of the Probable Maximum Flood (PMF) estimates that spillways of dams are required to pass. In many cases spillways were not designed with spare capacity and are incapable of safely passing the new PMF estimates. Dealing effectively with the potential for dams to cause damage and loss requires a risk management approach. Such an approach requires more reliable tools for estimation of rainfall. This paper examines the issues, the progress made, and outlines further work and options for clarifying risk.
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Robert E Saunders
The vast majority of dams in Australia are relatively small affairs. For example, approximately 90% of Queensland’ referable dams are less than 15 m in height. Most of these dams are owned by small communities, mining companies or farmers, many of which have smaller operations than those of Australia’s larger dam owners. In many cases the dam represents the owner’s sole source of water supply.
Many smaller dam owners are unaware of the key factors affecting the safety and best management of their facilities. Added to this is a general lack of understanding of dam related issues by the community at large. This often leads to significant owner and community concerns (and conflicts) that have the potential to jeopardise the viability, or worse, the safety of a project. The relative importance of the dam to the smaller dam owner often exacerbates these issues.
This paper serves to illustrate, by way of example, a consultant’s viewpoint of some of the issues encountered on small dam projects and suggests actions that the dams industry as whole could take to improve the situation.
Duane M. McClelland and David S. Bowles
There is a growing concern about the limitations of the approaches to life-loss estimation that are currently used in dam safety risk assessment. This paper summarises insights into factors that affect evacuation effectiveness, loss of life, and survival, based on a detailed review of historical dam breaks and other types of floods. The understanding and empirical characterisation of life loss dynamics being developed from these case histories are intended to provide the foundation for an improved practical life-loss estimation model.
P. J. N. Pells and M. Hunter
The potential for generating acid leachate from waste dumps is a major consideration in many metalliferous and coal mines. This paper describes the construction of the highest embankment dam in Indonesia for the sole purpose of storing potentially acid producing waste under water. The paper discusses the features of embankment dam design peculiar to an open pit mining environment which involves moving more than three times the total volume of earth and rock than in the whole of the Snowy Mountains Scheme.
Garry Meinck, Chris Elliott and Tony Moulds
This paper describes the experiences of a former state statutory authority in the almost four years since it became corporatised to form a water utility with a fully commercial orientation and with a new board of management with a clear awareness of the responsibilities of corporate governance.
The need to commit to major remedial work at one of the principal dams focussed the Board’s attention on the safety status of all of the Corporation’s 56 referable dams.
In the absence of external dam safety regulation the Corporation has moved to satisfy its corporate governance responsibilities by adopting current best practice in dam safety. Key elements in this process were:
Peter Quinlan and Sergio Giudici
The Hydro Electric Corporation (HEC) owns and manages 54 large and referable dams across Tasmania. Monitoring, data storage and data utilisation techniques have evolved significantly over the years as the dams have aged and as instrumentation, communication and data management technologies have advanced. This paper describes the development of the HEC’s ‘Asset Safety Evaluation Tool’ (ASET) for acquisition, management and interpretation of data relating to dam safety management. The paper also provides examples of how ASET has been applied within the HEC to demonstrate how the primary functional development goals of robustness and practicality have been achieved.