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Tantangara Dam

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32-662: Tantangara Dam is a major ungated concrete gravity dam with concrete chute spillway across the Murrumbidgee River in Tantangara , upstream of Adaminaby in the Snowy Mountains region of New South Wales , Australia . The dam is part of the Snowy Mountains Scheme , a vast hydroelectricity and irrigation complex constructed in south-east Australia between 1949 and 1974 and now run by Snowy Hydro . The purpose of

64-633: A 1.50 m (4 ft 11 in) diameter nozzle to the river diversion tunnel, with a capacity of 70.8 m/s (2,500 cu ft/s). The Snowy Water Initiative (SWI) is an agreement for water recovery and environmental flows between the NSW, Victorian and Australian Governments, and Snowy Hydro Limited (SHL) which is set out in the Snowy Water Inquiry Outcomes Implementation Deed 2002 (SWIOID 2002). The SWI provides three main environmental water programs as part of rebalancing

96-540: A gated release structure is available. Accordingly, the daily flow release strategy for the Murrumbidgee River differs from the other SMRIF release points. The releases comprise two components: (i) the SMRIF and (ii) a Base Passing Flow (BPF). The BPF has some key components, these being: The Base Passing Flow releases typically occur during drier weather. A modified 'flow scaling' approach used to set SRIF releases to

128-628: A lack of regulatory resources. In 2005, the Australian Capital Territory Government explored the options of augmenting water supply for Canberra by developing a long tunnel alternative including weir, connecting tunnel, outflow pipes, and hydro-power plant construction to link the Murrumbidgee with Corin Reservoir; and/or a Murrumbidgee River flow alternative including weir, pumping station and pipeline construction to link

160-555: A target of 27 GL (i.e. 30% of the Mean Annual Natural Flow- MANF) in a full allocation scenario. Since 2005–06, environmental water has been released to the Upper Murrumbidgee River to repair the condition of the river. Over the period 2005 to 2018, an average of 17.7 GL per year of environmental water has been released to the upper Murrumbidgee River. The annual allocation varied between 4 GL per year during

192-407: Is 2,117.7 ha (5,233 acres) and the catchment area is 460 km (180 sq mi). The spillway across the Murrumbidgee River is capable of discharging 900 m/s (32,000 cu ft/s). Water flows 16.6 km (10.3 mi) from Tantangara Reservoir to Lake Eucumbene via the 3.1–3.35 m (10.2–11.0 ft) diameter Murrumbidgee-Eucumbene tunnel falling 40 m (130 ft) in

224-401: Is determined by the water recovery in the western rivers and the preceding climatic conditions. The SWIOID 2002 provides for SHL to forego up to 150 gigawatt hours (GW h) of electricity generation to allow for environmental releases to be made to SMRIF. This value of 150 GW h is converted into a volumetric allocation, but the conversion factor differs depending on the location of the releases in

256-474: Is that their large concrete structures are susceptible to destabilising uplift pressures relative to the surrounding soil. Uplift pressures can be reduced by internal and foundation drainage systems. During construction, the exothermic curing of concrete can generate large amounts of heat. The poorly-conductive concrete then traps this heat in the dam structure for decades, expanding the plastic concrete and leaving it susceptible to cracking while cooling. It

288-406: Is the designer's task to ensure this does not occur. Gravity dams are built by first cutting away a large part of the land in one section of a river, allowing water to fill the space and be stored. Once the land has been cut away, the soil has to be tested to make sure it can support the weight of the dam and the water. It is important to make sure the soil will not erode over time, which would allow

320-810: The Australian Capital Territory Government or ACT Government , is the executive branch of the Australian Capital Territory . The leader of the party or coalition with the confidence of the Australian Capital Territory Legislative Assembly forms government. Unlike the Australian states and the Northern Territory , the Legislative Assembly directly elects one of their number to be the Chief Minister as

352-449: The weight of the material and its resistance against the foundation. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. Gravity dams generally require stiff rock foundations of high bearing strength (slightly weathered to fresh), although in rare cases, they have been built on soil. Stability of the dam primarily arises from the range of normal force angles viably generated by

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384-688: The Australian Capital Territory (Self-Government) Act 1988. Nonetheless, the ACT is governed according to the principles of the Westminster System , a form of parliamentary government based on the model of the United Kingdom . Legislative power rests with the unicameral Australian Capital Territory Legislative Assembly . Executive power rests formally with the Executive, which consists of

416-571: The Australian States and the Northern Territory . In the ACT, government functions that would usually be handled by local government are instead directly handled by the Territory government. The current arrangement of the incumbent ministry ( Fourth Barr Ministry ) of the ACT was appointed on 6 November 2024, comprising eight Labor Party members. The current arrangement of the incumbent shadow ministry

448-720: The Chief Minister and Ministers, and is informally called the Cabinet . Judicial power is exercised by the Supreme Court of the Australian Capital Territory and a system of subordinate courts, but the High Court of Australia and other federal courts have overriding jurisdiction on matters which fall under the ambit of the Australian Constitution. The ACT does not have a separate system of local government such as that seen in

480-489: The Chief Minister. The current ministry of the Australian Capital Territory ( Fourth Barr Ministry ) comprises eight of the 25 members of the Legislative Assembly. The ACT has internal self-government, but Australia's Constitution does not afford the territory government the full legislative independence provided to Australian states. Government for the Australian Capital Territory is outlined in Commonwealth legislation;

512-776: The Murrumbidgee with Googong Reservoir . In 2009, the ACT Government endorsed a recommendation from ACTEW for implementation of the Tantangara Transfer Project, that involves transferring water from the Murrumbidgee River (below the Burrinjuck and Blowering dams) in New South Wales to the ACT via the Snowy Mountains Scheme. The reservoir is a key part of the Snowy 2.0 Pumped Storage Power Station . It will act as

544-480: The Snowy Mountains Scheme, and thus influence the overall volume released. In some locations water released can be re-used to generate electricity so a smaller conversion factor is applied (SWIOID 2002), however, where water is lost to the Snowy Scheme a higher conversion factor is applied. Releases to the Murrumbidgee River are made from Tantangara dam, a much larger structure than the other release points, for which

576-581: The Snowy River has also been applied to the SMRIF in the Murrumbidgee River (;). This modified approach uses the recorded flows in a nearby natural catchment (in a year where similar volumes of flow occurred) to set daily releases. For releases to the Murrumbidgee River from Tantangara dam, the initial daily flow targets were set using the flow sequence for the Murrumbidgee River above Tantangara (station No. 410535). Daily targets are then amended to account for operational implementation. The SWIOID 2002 identifies

608-673: The basis for river recovery, rather than the traditional Australian e-water approach of managing rarity of aquatic biota. A 2011 report by the Snowy Scientific Committee stated that the Tantangara Dam was starving the upper Murrumbidgee River of environmental water flows from the Snowy Mountains; needed to restore river health. The committee claimed that there was an apparent "administrative and managerial void", with no river management strategy and no proper monitoring because of

640-495: The biggest danger to gravity dams and that is why, every year and after every major earthquake, they must be tested for cracks, durability, and strength. Although gravity dams are expected to last anywhere from 50–150 years, they need to be maintained and regularly replaced. Government of the Australian Capital Territory The Government of the Australian Capital Territory , also referred to as

672-607: The dam can begin. Usually gravity dams are built out of a strong material such as concrete or stone blocks, and are built into a triangular shape to provide the most support. The most common classification of gravity dams is by the materials composing the structure: Composite dams are a combination of concrete and embankment dams . Construction materials of composite dams are the same used for concrete and embankment dams. Gravity dams can be classified by plan (shape): Gravity dams can be classified with respect to their structural height: Gravity dams are built to withstand some of

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704-583: The dam in 1959, during its construction. The dam was constructed by Utah-Brown & Root Sudamericana on behalf of the Snowy Mountains Hydro-Electric Authority , and is now managed by Snowy Hydro Limited. The concrete gravity dam of 73,800 m (2,610,000 cu ft) is 45 m (148 ft) high, with a crest length of 216 m (709 ft). At 100 per cent capacity, the dam wall holds back 254,099 ML (206,001 acre⋅ft) of water. The surface area of Tantangara Reservoir

736-549: The dam includes water management and conservation, with much of the impounded headwaters diverted to Lake Eucumbene . The impounded reservoir is called Tantangara Reservoir . Commenced in 1958 and completed in 1960, the Tantangara Dam is located on the Murrumbidgee River, approximately 6 km (3.7 mi) downstream of its confluence with Gurrangorambla Creek and is wholly within the Kosciuszko National Park . Her Royal Highness Princess Alexandra of Kent visited

768-431: The drought and 42.3 GL per year once sufficient water had been recovered. The environmental water portfolio does not allow for environmental water to be released everyday of the year from Tantangara Dam. Over the period 2005 to 2018, various environmental flow strategies have attempted to re-instate a winter-spring montane flow pattern. These approaches have attempted to improve instream habitat and ecological processes as

800-434: The foundation. Also, the stiff nature of a gravity dam structure endures differential foundation settlement poorly, as it can crack the dam structure. The main advantage to gravity dams over embankments is the scour -resistance of concrete, which protects against damage from minor over-topping flows. Unexpected large over-topping flows are still a problem, as they can scour dam foundations. A disadvantage of gravity dams

832-507: The head of the government, rather than being appointed by a Governor or Administrator. Since December 2014, the Chief Minister has been Andrew Barr , leader of the Labor Party . Following the 2024 ACT election , Labor formed a minority government of 10 members, after the Greens moved to the crossbench and dissolved the coalition that had been in place since 2012. Ministers are appointed by

864-483: The impacts of the Snowy Hydro Scheme on montane rivers. These three programs are increased flows for: (i) Snowy River, (ii) River Murray, and (iii) Snowy Montane Rivers. The Snowy Montane River Increased Flows (SMRIF) program identifies five montane rivers to receive environmental water. The water availability for SMRIF is linked to the water availability for Snowy River Increased Flows (SRIF) (Williams 2017), which

896-481: The process. Flow is controlled by a 1.83 m × 2.13 m (6 ft 0 in × 7 ft 0 in) regulating gate such that a maximum of 20 m/s (710 cu ft/s) is allowed. Flow downstream into the Murrumbidgee River is controlled at the dam and comprises two shafts, 2.13 m × 3.05 m (7 ft 0 in × 10 ft 0 in) at the outlet tower and tapering to 2.13 m (7 ft 0 in) diameter before passing through

928-485: The strongest earthquakes . Even though the foundation of a gravity dam is built to support the weight of the dam and all the water, it is quite flexible in that it absorbs a large amount of energy and sends it into the Earth's crust. It needs to be able to absorb the energy from an earthquake because, if the dam were to break, it would send a mass amount of water rushing downstream and destroy everything in its way. Earthquakes are

960-589: The top storage for a pumped hydro power station. Water levels are held at 20% in the summer months so that the Port Philip Trail remains above the water. There are good populations of both brown trout and rainbow trout within the reservoir. The wet winter of 2016 saw levels exceed 70% in October- the highest for 2 decades. Gravity dam A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only

992-493: The water to cut a way around or under the dam. Sometimes the soil is sufficient to achieve these goals; however, other times it requires conditioning by adding support rocks which will bolster the weight of the dam and water. There are three different tests that can be done to determine the foundation's support strength: the Westergaard, Eulerian, and Lagrangian approaches. Once the foundation is suitable to build on, construction of

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1024-463: Was announced on 18 November 2024, comprising seven Liberal Party members. The ACT Government is served by a unified ACT Public Service agency , reporting to a single Head of Service. Administrative units, known as Directorates, are grouped under areas of portfolio responsibility. Each Directorate is led by a Director-General who reports to one or more Ministers. As of November 2020 , there are nine Directorates: The ACT Government also has

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