Damon Miller and Grant Jones
Mt Buller Alpine Resort has significant constraints on its capacity to store and supply potable water during times of peak demand, which impacts the ability to sustain and grow visitation to the resort, limiting optimal functioning and future development of the resort.
A proposed new 100 megalitre dam would primarily supply the resident and visitor populations with a reliable potable water source while also maintaining through snowmaking, the Resort’s amenity and functionality during winter for skiing and snow-play.
Standard dam engineering criteria of technical feasibility and environmental impact influenced the site selection and design of the new off-stream storage whilst additional key drivers unique to an alpine resort, framed around impact to existing skiable terrain and resort functionality, were critical to satisfy the resort stakeholders. The need to minimise the visual impact of the dam and integrate with the resort environment was also of high importance.
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Lyndon Johnson and Jamie Campbell
Data presentation is an important and much discussed aspect of Dam and asset safety worldwide. We rely on drawings and graphs of instrumentation data to tell us things about our assets that are hidden from the eye and to monitor changes linked to failure modes. It’s common that we look at data gaps for our assets, data quality and data processing but how often do we rethink the fundamentals of data presentation?
Engineers and data analysts, as humans, have evolved in a 3D world with our senses to match match. According to Keller GB, et al (2012) almost 20% of the human brain is dedicated to processing vision with up to 60% involved when locating, scaling and referencing objects in 3D space. As a result, 3D is an extremely efficient platform from which to display and disseminate information.
This paper discusses methods to efficiently transfer asset information into 3D and how to present animated surveillance data against asset models. The paper discusses how these methods work, benefits and limitations in the context of modern dam asset portfolio management and presents some key case studies of where and how these methods have assisted with asset diagnoses.
Guresh Ahuja, Brian Cooper, Olaf Rutgrink and Andrew Thomson
This paper presents details of the State Water Corporation of NSW Australian first temperature control curtain project aimed at dealing with the environmental issue of cold water pollution in dam offtakes. This is a key project focused on dealing with a known environmental issue and reflects changing environmental and social expectations for dam operators. In the concept phases this project was part of the NSW Rivers Environmental Restoration Program (RERP) sub-program ‘better delivery of environmental water’.
The paper presents the development of the design concept including early concept screening and selection, scale model testing, concept design development, hydrodynamic, structural and computational fluid dynamic analyses leading to the final design that has now being constructed. The concept design work was completed in 2011 and following a tender process a design and construct contract was let for the detailed design and construction of the temperature control curtain system. This phase of the work was recently completed and the temperature control curtain is now fully operational. The actual performance and effectiveness of the temperature control curtain will only become evident after a few years of operation and will also hinge on the degree of stratification in the dam.
Robert Kingsland, Andy Noble and Dr Eric Lam
Engineering design is necessarily context specific. However, engineering design produced in industrialised nations often comes encumbered with design methods, standards and construction process familiarities that can result in inappropriate design solutions for developing nations. This is no more apparent than with the design of small hydropower projects where budgets are small and the implications of poor decisions can easily threaten the viability of schemes.
In this paper we explore the challenges and opportunities for the scheme’s developer and designer, in striking an appropriate balance on engineering solutions that remain appropriate for the local construction practices. In most cases, based on our experiences from small, run-of-river developments, the available methods for feasibility study data collection, including geotechnical investigations and hydrology assessments, are in themselves a challenge. Consequently, the designer needs to work with what is readily available and often has to reset the established thinking to incorporate practical constructability into the designs, while giving special attention to the operation and maintenance aspects. More labour-intensive methods are not uncommon.
The stakeholders in small hydropower schemes are many: the community, the approval agencies, the lenders, the developers, the local construction industry, the government. Design decisions cannot be made in a vacuum. However, designers are often distant from the social, political, environmental and commercial context of their project. This separation can present significant challenges which, without due attention, can result in poor design outcomes.
This paper will, with reference to examples of good and poor design, discuss various facets of small hydropower development from a civil engineering perspective including, the scale of development, design methods, stakeholder engagement, local content involvement, constructability and financing. The paper concludes with suggestions for improving design outcomes for small hydropower projects.
Kathryn Whalley and Bob Clark
When Seqwater was established in 2008 it inherited from local governments 51 weirs of varying ages, sizes, design standards and condition. In order to better understand these structures, in 2012 Seqwater engaged NSW Public Works to undertake a condition and risk assessment of its weir portfolio. The assessment, consisting of a background review, site inspections, stability assessment and a collaborative risk workshop, examined risks to the structures, to Seqwater personnel and the public. Assessment of the risk consequences used Seqwater’s recent experience with repairs to weirs damaged in the 2011 and 2013 Queensland floods. The assessment was completed in 2013 and identified more than 1000 risks. It was recommended that more than 600 moderate to high risks be reduced through a prioritised program over the next 10 years. Weir performance following the 2011 and 2013 floods is also discussed.
Andrew Richardson, Stephen Farrelly and Phil Farnik
In 2012 an update to the Portfolio Risk Analysis (PRA) was undertaken by State Water Corporation for its 18 major dams in New South Wales. The updated portfolio level risk analysis of all the dams has taken account of the completion of major components of the 2006 dam safety upgrade program, while also incorporating continued engineering research into dam safety performance. This paper will provide an overview of the approach, the challenges faced in the process and it will highlight the innovative advances made representing industry best practice. Some future implications and directions will also be discussed.
The three main components of the PRA update in 2012 have included a significant amount of dam break hydraulic modelling including revised hydrology and flood inundation mapping delivered in-house by State Water with consultant support. The Consequence Assessment was developed with a spatial link to natural flooding and dam failure consequences by Sinclair Knight Mertz (SKM), while the third element in producing the event trees, risk analysis and PRA reports was undertaken by consultants GHD. Peer review of the PRA process and reports and additional technical review of the failure modes and event trees by a panel of industry experts provided the necessary independent input and oversight required by the NSW Dams Safety Committee.
State Water’s PRA update builds on the large body of work undertaken for and since the last PRA in 2002. The update process has applied a systematic and quantitative approach across the Portfolio that provides a robust basis for managing dam safety risk. The results of the PRA have identified further work required to investigate and assess the need for dam safety upgrade options for non-compliant dams. State Water’s investment in the PRA has produced a risk-based position on each dam in the portfolio that can be used to identify a range of measures in a revised dam safety upgrade program for the future.