2005 – Environmental Involvement
Stuart Macnish, Natarsha Woods, Michael Dixon
What happens when the people that undertake early environmental investigation stay on as part of the delivery team throughout the design and construction phases of a major project such as the Wivenhoe Alliance?
Often, the early investigation for projects, particularly in the case of environmental impact assessments and approvals processes, is carried out independently of the construction team. In the case of the Wivenhoe Alliance, these issues were set out in the scope of the project itself and delivered by the same team during construction.
The benefits and outcomes have been impressive not only for the project, but for SEQWater and the local community into the future. Improved biodiversity values, increased water quality protection, safety improvements, and value for money are only some of the key benefits experienced.
Individuals within the team also benefit. Environmental professionals are able to implement their
knowledge ‘on-ground’ and progressively improve practices in an area of constant change due to
construction initiatives and timeframes.
This paper explores the specific areas in which the involvement of environmental professionals throughout early investigation and planning, design and construction have benefited the Wivenhoe Alliance and the outcomes that have resulted from this innovative approach.
$15.00
Now showing 1-12 of 64 2969:
Related products
-
$15.00
2005 Papers
2005 – Dam Safety Emergency Exercise for Eildon Dam, Goulburn Weir and Waranga Basin
Learn moreAndrew Evans, Michael Cawood, Jonathon Reid
Eildon Dam, Goulburn Weir and Waranga Basin in Victoria are owned and managed by Goulburn-Murray Water (G-MW). Eildon Dam and Goulburn Weir are situated on the Goulburn River, while Waranga Basin is an offstream storage supplied from Goulburn Weir.
In November 2004 a dam safety emergency exercise involving the establishment of a central Emergency Coordination Centre at Tatura as well as Emergency Operations Centres at each of these three dam sites was conducted. The exercise presented a variety of emergency situations in stepped time increments, including earthquake, mechanical failure, a hazardous material spill and a terrorism related incident. External agencies were not involved.
The exercise was part of an ongoing G-MW program designed to test and improve dam safety emergency planning and response systems for all of G-MW’s dams and highlighted areas where procedures, situational management and communications can be enhanced.
Outcomes aimed for in G-MW’s program are improvement in Dam Safety Emergency Plans and internal communications, together with clarification of roles, responsibilities and capabilities.
Learn more
The valuable experiences learned from this dam safety emergency exercise and plans for a larger scale exercise involving other emergency management agencies will be shared with others through this paper. -
$15.00
2005 Papers
2005 – Blowering Dam – Spillway Hydraulic Modelling
Learn moreDavid Ho, Karen Riddette, Michael Hogg, Jayanta Sinha and John Roberts
Blowering Dam was constructed in 1968 by the Snowy Mountains Hydro-Electric Authority, on behalf of the Water Conservation and Irrigation Commission. It is a large earth and rockfill embankment dam, approximately 112m high and 808m long, with a concrete chute spillway at the right abutment. The reservoir holds about 1,628GL of water that is mainly for irrigation and supplying an 80MW hydro-electric power station. The dam is owned and operated by State Water Corporation, NSW.
Revisions to the design flood estimate have highlighted the dam requiring an upgrade to cope with increased discharge rates. The NSW Department of Commerce has carried out feasibility studies of different upgrade options. The need to evaluate the hydraulic performance of the existing un-gated spillway was identified. Flow overtopping the chute walls can potentially erode the backfill behind the walls, and, the rockfill on the downstream toe of the embankment. Consequently, this may lead to significant damage of the spillway and may risk the safety of the dam.
Hydraulic analysis of the spillway using a 3-D computational fluid dynamics model was performed for
various flood levels to determine the discharge coefficients and the discharge rating curve. It was also required to identify whether the chute walls need raising to contain the increased discharges. These results were compared with those calculated by other “standard” methods. Such verification provided a level of confidence in the analysis results which were then used in the studies to assess available upgrade options.In order to have further confidence in the analysis, the computed results were validated against physical test data and some limited information from an actual discharge. Further verification against established theory was conducted by modelling a supercritical flow through a contraction in an open-channel in order to see if the computation could predict the shock wave effect that was observed in physical models as well as full scale channels. A reasonably good correlation was obtained from all validating tests.
This paper presents some background of the proposed dam upgrade, potential upgrade options considered and details of the hydraulic modelling of the spillway. Some interesting flow behaviour caused by the shock wave will be highlighted.
Learn more -
$15.00
2005 Papers
2004 – Communicating Dam Safety Practices to the Community for a 60km Long Canal Hydro Development in New Zealand
Learn morePeter D Amos, Pip Nicolson, M Grant Webby, Murray D Gillon
To obtain a resource consent to build and operate any new water resource or hydro-electric development in New Zealand, the developer is required by the Resource Management Act (RMA) to consult with the community over the effects that the development could have, including describing how public safety risks will be avoided, remedied or mitigated. The community has the opportunity to respond to the authorities issuing the resource consent and influence the conditions attached to the consent.
The proposed Project Aqua Scheme in the South Island, New Zealand, comprised a 60 km long canal system to convey 340 cumecs flow from the Waitaki River across alluvial river terraces and through a chain of six hydro-power stations before returning the water back to the river. Each section of canal between stations would have contained between 4 and 6 million m3 of water within embankments up to 20m high. A breach of any one of these canals had the potential to flood farmland, residential buildings, highways, and other infrastructure, thereby posing a safety risk to local residents together with the potential for significant economic loss.
The paper describes the methodologies that were developed and used to assess the impacts, the measures proposed to avoid, remedy or mitigate safety risks and the public reaction to the associated report that was provided for public consultation prior to abandonment of the project. The methodologies used required adaptation of dam safety and consequence assessment practices usually applied to in-river dams, and applied here to the 60 km long length of canal embankment.
Learn more -
$15.00
2005 Papers
2005 – RISK ASSESSMENT AND UPGRADE OF THE VALVES AT THE WARRAGAMBA DAM OUTLET WORKS
Learn moreWarragamba Dam supplies up to 80% of Sydney’s water needs and is currently undergoing a range of major infrastructure upgrades. The outlet works upgrade is one of these projects. The outlet works of the dam were constructed in the 1950s and consisted of four 2100mm pipes with isolating gate valves and needle control valves feeding two large above ground pipelines running 27 kilometres east to Prospect Reservoir in Sydney’s western suburbs.
In the 1990s the then dam owner (Sydney Water) undertook a detailed and extensive risk analysis of the outlet works. The study resulted in a recommendation to remove the existing valves and replace them with a combination of emergency closure (guard) valves and isolating valves. Under the Sydney Catchment Authority (the present dam owner) work subsequently proceeded in 2004 as a design and construct contract with all aspects of construction and water supply risks identified. Stringent controls were developed and placed on work programs and pipeline shutdowns to ensure the safety of all involved and the integrity of the supply to Sydney.
The four outlets required eight large valves, which were manufactured in Germany and were required to meet stringent operational requirements.At the time of writing three of the four outlets have been successfully upgraded and commissioned. Work has commenced on upgrading the fourth outlet, which is due for completion by the time of the conference, approximately 20 months ahead of schedule.
Learn more
This paper discusses the project from the initiation of the risk analysis study, through the
consideration of options, development of the contract, and the supply, installation and commissioning of the large valves and pipe work. It highlights the role of risk assessment in selection of the preferred option and addresses some of the engineering challenges faced during the project. -
$15.00
2005 Papers
2005 – Importance of Streamflow Monitoring for Sam Safety and Water Supply Security
Learn moreIan Cordery, Peter S. Cloke
Scientists advocate more hydrological monitoring but in most regions publicly funded monitoring is in
steady decline. The lack of measured data at dam sites means there are many designs for new dams and remedial work that are insufficiently supported by factual information. Unfortunately data –free modelling exercises will usually produce favourable results – favourable to the modeller’s purposes, but not necessarily favourable to the determination of physical reality or truth. In these days of the popularity of modelling it is common to find decisions being made based on model studies for which little or no local data were available for model calibration or verification. How can the ‘large dam’ fraternity encourage (ensure) more data use? Causes of lack of data are many. For example governments fund data collection but others need the data, and data collection is a long-term activity that produces few benefits in the short term. Some years ago it was shown that hydrological data collection and archiving provided benefits to the community of at least nine times the costs of the data.The real costs of comprehensive data collection are not large but examples will be given of the huge
Learn more
costs, mainly due to the need to allow for uncertainty, that result from unavailability of data. Those
who understand this problem need to explain it to their communities, politicians and CEOs in a clear,
unmistakably persuasive manner, and to demand an increase in data collection. If we do not, no one
else will.