As New Zealand’s largest dam owner, ECNZ has actively managed dam safety since its inception in 1987. During this time it has managed several major dam safety issues and enhanced its dam safety management practices. This has occurred in an environment of organisational change and increasingly competitive commercial pressures.
The change in emphasis from a primarily technical emphasis to dam safety towards a commercial focus is described together with details of highly rated dam surveillance system, some continuous improvement initiatives, and recent enhancements to the dam safety programme. The position of responsible ownership in regard to risk and legal requirements is also discussed.
— OR —
Now showing 1-12 of 31 2948:
R J Westmore and P J Cummins
Wartook Reservoir is owned and operated by the Wimmera Mallee Rural Water Authority in western Victoria. The reservoir was constructed in the period 1887 to 1890 on the Mackenzie River within the Grampians National Park. It has a capacity of 29400 ML, is the sole supply of water to the City of Horsham, and also supplies stock, domestic and irrigation water to the Wimmera and Mallee Regions of Victoria.
The embankment is 1100 m long, 12 m high and is constructed of loose to medium density silty fine sands which are susceptible to liquefaction during a seismic event due to the combination of high pore water pressures and low density. Active seepage from the embankment and foundations render the embankment susceptible to failure by piping.
The outlet works were constructed of sandstone masonry and comprise a tower and cut-and- cover conduit buried within the embankment. Inflow of fine sands from the embankment into the masonry tunnel render the embankment susceptible to failure by piping through the joints in the masonry tunnel.
Design concepts for the rehabilitation of the embankment, outlet and spillways have been developed jointly between Wimmera Mallee Water and SMEC Victoria adopting a risk based approach. The design involves partial rehabilitation of the works, providing acceptable levels of risk to the Authority and community, at an economically justifiable cost.
David Watson and John Adem
For several years risk management has been promoted by the Victorian Department of Natural Resources and Environment – Water Agencies as the key mechanism for the effective and efficient business management of dams. As part of an extensive water reform program, the Victorian Government announced in October 1997, a financial assistance package for the water industry which included funding for dam improvements covering a majority of large dam owners in the State. One of the conditions for receipt of these improvement funds was the need for each water authority to undertake a Business Risk Assessment of all significant and high hazard dams under its responsibility.
This paper discusses the Business Risk Assessment document based on a framework developed by Water Agencies after consultation with the industry and expands on the following reasons why the document was produced:
David Dole and Brian Haisman
The Murray-Darling Basin Commission recently created River Murray Water, an internal business unit, as a step towards the micro-economic goals of the COAG Water Reforms.
The assets which regulate the River Murray, have a replacement value around $1.4 billion. They range from the 4000 gigalitre Dartmouth Dam in the headwaters, to the 7.5 kilometres of barrages near the Murray mouth and are presently held in trust for the Contracting Governments of the Basin Initiative by one or other of the three riparian states. River Murray Water is bringing the assets together into a single, integrated business with the aim of securing long-run sustainability, funded through pricing for services provided. Broad institutional and pricing principles are described along with the special challenges of an inter-government environment.
These challenges are being met by adopting clarity and simplicity as driving principles, supported by best practice asset information. The paper describes the upfront development of explicit guiding principles and policies, including risk management and dam safety; coordination of activities; generation of life cycle information; and introduction of contestable service provision for the business.
D. C. Green
The disaggregation of public water supply bodies in recent years has seen the functions of ownership, design and operation transferred to separate bodies. Consequently , issues of risk management associated with legal liability which previously could be ignored because all risks were absorbed in -house must now be faced and addressed in a more formal way.
This paper looks firstly at the general principles of legal liability for dam performance associated with construction and design, ownership of an existing dam and monitoring of its performance. Liability under several different areas of the law is discussed. Special issues associated with “design and construct” contracts are then highlighted, and warnings are given for project sponsors who control the letting of contracts and the briefing of consultants.
Gary Gibson, Wayne Peck, Ian Landon-Jones and Kumara Arachchi
One of the first seismograph networks designed specifically to record local earthquakes was installed about Sydney in 1958. This network was converted to telemetry in 1983. In 1992, Sydney Water Corporation upgraded the network, integrating the functions of earthquake location and magnitude, measurement of the response of structures to earthquake motion, and provision of information for emergency response. The response function has been developed over the past six years, and is now an “Earthquake Preparation, Alarm and Response” system that provides customised information very soon after any significant event.