20-631: The Trevallyn Dam is a dam on the South Esk River in Launceston , Tasmania, Australia and is used to provide water for hydroelectricity . The dam was completed in 1955 as part of the Trevallyn Hydro Electric Scheme and now holds the waters of Lake Trevallyn. Lake Trevallyn is a concrete gravity dam built on Dolerite bedrock. The spillway height is 26.8 metres and the dam wall is 177 metres long. The lake has
40-461: A 3.3-kilometre (2.1 mi)-long penstock pipeline to the power station. Water flows underground for its entirety except for a short, 100-metre (330 ft)-long portion that leaves the ground near Pitt Avenue due to a valley intersecting the tunnel's course. The pipeline splits underground into four smaller pipes immediately before entering the station's turbines. The water enters the penstock tunnel 130 metres (430 ft) above sea level and leaves
60-460: A check on algal levels and to notify authorities when blooms occur. In 2009, scientists discovered the freshwater jellyfish, Craspedacusta sowerbyi , in the waters of Lake Trevallyn close to Blackstone Heights. Believed to have been brought by migrating birds from China , the jellyfish were accidentally discovered during routine water testing. The jellyfish are non-venomous and translucent with average sizes around 2 cm across. Though introduced,
80-524: A combined generating capacity of 95.8 megawatts (128,500 hp) of electricity. Within the station building, each turbine has a fully embedded spiral casing. A main inlet valve is located in the station immediately upstream of each turbine for maintenance and security purposes. No. 1 and no. 2 machines are equipped with a turbine relief (bypass) valve to reduce pressure rise in the turbine and penstock during rapid guide vane closure. The station output, estimated to be 492 gigawatt-hours (1,770 TJ) annually,
100-490: A surface area of 1.48 km (0.57 sq mi) and storage capacity of 12,330,000 m (435,000,000 cu ft). ANCOLD lists Trevallyn Dam as having a dam wall height of 33 metres and the total volume of the wall as 61,000 m (2,200,000 cu ft). The dam diverts water to the Trevallyn Power Station through a 3.2 km tunnel. Lake Trevallyn is the long, narrow lake created by
120-611: A word for the Fingal Valley) and mooronnoe (the Northern reach around modern day Hadspen). The South Esk River runs through, and forms the borders of, traditional lands of two nations of the Palawa. The Ben Lomond Nation occupied territory enclosed by the river's western and southern stretches and occupied the entire upper reaches as far as its northern watershed. The Panninher, Tyrernotepanner and Leterremairrener clans of
140-468: Is fed to TasNetworks ' transmission grid via two three-phase Alstom generator transformers and two 3-phase English Electric generator transformers to the outdoor switchyard. Water is discharged into the Tamar River at sea level by an open tailrace channel. The construction village, named Marrawaylee, is now part of the suburb of West Riverside and is accessed by Pomona Road. The power station and
160-738: Is situated on the Great Lake and South Esk catchment and is owned and operated by Hydro Tasmania . Part of the Great Lake and South Esk scheme that comprises three hydroelectric power stations, the Trevallyn Power Station is the final station and is located adjacent to the Tamar River north of Launceston , making use of daily flows down the South Esk River. A dam on the South Esk River diverts water through
180-595: The North Esk River at Launceston . From this confluence arises kanamaluka /Tamar River, which runs to the Bass Strait . The natural river flow is interrupted by the Trevallyn Dam, near Launceston, constructed as part of the Trevallyn Power Station hydroelectric power scheme. The river is subject to flooding which overflows at Lake Trevallyn to create the spectacle of high rapids coursing through
200-475: The North Midlands Nation occupied the territories to the west of the river. The Aboriginal clans exploited the hunting grounds alongside the river and took the native freshwater mussel for food. The river was frequented by Aboriginal people and remnants of their campsites and toolmaking have been found along the river. The ethnographic record describes particular meeting areas, or 'resorts', on
220-608: The dam and extends as far as Hadspen where the first rapids begin at the junction of the Meander and South Esk Rivers . The widest point on the lake is at Stephenson's Bay where it reaches 390 m wide. Launceston's outer suburb of Blackstone Heights and part of the Trevallyn State Recreation Area form part of the shore of Lake Trevallyn. Land around the lake is a mixture of suburbs, agricultural land and dry eucalypt forest. The lake and some of
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#1732776225457240-443: The dam and penstock intake. Lake Trevallyn is often prone to algal blooms in the warm summer months. The blooms are due to high nutrient levels from sewerage treatment and fertilizers, limited water movement and warm temperatures. The main species is Anabaena circinalis and though it has the potential to be toxic, no blooms recorded in the lake have proven to be toxic to date. Since 2007, a monitoring program has been in place to keep
260-530: The eastern foothills of the Ben Lomond plateau near Mathinna and the river's course describes an arc around the entire southern promontory of the mountain – running through Fingal , Avoca and Evandale before winding its way northwest through Perth , Longford and Hadspen . The river merges with the tributary Meander River , then flows through the narrows of the Cataract Gorge to finally meet
280-465: The entire north Midlands valley, the watersheds of the Western Tiers, Ben Lomond plateau and Eastern Ranges south of Ben Lomond. The river is known in palawa kani, the language of Tasmanian Aboriginal people, as plipatumila. Other recorded Tasmanian Aboriginal names for the river are mangana lienta (from the word menanyer meaning 'large stream' and liena – either fresh water or related to
300-516: The jellyfish are believed to have a beneficial impact on the area as they consume the larvae of mosquitoes. A few specimens were temporarily displayed at the QVMAG in Launceston after the discovery was made. South Esk River The South Esk River , the longest river in Tasmania , is a major perennial river located in the northern region of Tasmania, Australia. The South Esk springs from
320-841: The narrows of the Gorge . The river's two largest tributaries are the Macquarie and Meander Rivers, with lesser tributaries being the Nile River, River Tyne, Storys Creek and the Break O'Day River – upstream of the junction with the Macquarie. The Meander's main tributaries are the Liffey River and Quamby Brook and the Macquarie's main tributaries are the Lake, Isis , Elizabeth , Blackman, and Tooms rivers. These tributary watercourses drain
340-523: The power station at sea level, entering the Tamar River via the Tailrace Bay on Tie-Tree Bend. Trevallyn and Poatina are the only hydroelectric power stations currently located in the drainage basin of the South Esk River. The tunnel through which the pipeline runs is cut through dolerite and was excavated by a French tunnelling company. The bay that the used water is discharged into was excavated using mostly steam driven equipment and tram ways with
360-490: The river; such as Stony Creek, near Llewellyn ; Glen Esk (near Nile); Native Point, near Perth ; and at Hadspen . The river was renamed by Colonel William Paterson in December 1804 after the eponymous Scottish river. Trevallyn Power Station The Trevallyn Power Station is a run-of-the-river hydroelectric power station located in the northern Midlands region of Tasmania , Australia. The power station
380-409: The surrounding land is used as a recreation area. Most facilities are located at Aquatic Point which include a boat launching ramp, jetty and ski-jump. A walking track connects Aquatic Point to the dam wall and Trevallyn State Recreation Area. The dam wall features a viewing platform, parkland and barbecue facilities. Most areas of the lake are open to boating and fishing with the exception of waters near
400-833: The two tailing mounds now forming the Tailrace Park (south side) and the Tailrace Convention Center (north side). The Tailrace Bay has been adapted to serve recreational purposed and also provides a safe anchorage for yachts. The power station was commissioned in 1955 by the Hydro Electric Corporation (TAS) , replacing the Duck Reach Power Station . The station has two 20.9-megawatt (28,000 hp) English Electric Francis-type turbines and two 27-megawatt (36,000 hp) English Electric Francis-type turbines, with
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