Crotty Dam

{{Short description|Dam in Tasmania, Australia}} {{Use Australian English|date=June 2015}} {{Use dmy dates|date=June 2015}} {{Infobox dam | name = Crotty Dam | name_official = | image = Mount Jukes and burbury.JPG | image_size = 240 | image_caption = Crotty Dam (at right) aerial shot from the east | image_alt = | location_map = Australia Tasmania | location_map_size = 240 | location_map_caption = Location of the dam in [[Tasmania]] | location_map_alt = | mapframe = yes | coordinates = {{coord|-42.160151|145.61657|type:landmark_region:AU-TAS|display=inline,title|format=dms}} | country = Australia | location = [[West Coast Tasmania]] | purpose = P | status = O | construction_began = | opening = 1991 | demolished = | cost = | owner = [[Hydro Tasmania]] | operator = | dam_type = H | dam_crosses = [[King River (Tasmania)|King River]] | dam_height = {{cvt|83|m}} | dam_height_foundation= | dam_height_thalweg = | dam_length = {{cvt|245|m}} | dam_elevation_crest = | dam_width_crest = {{cvt|300|mm}} | dam_width_base = | dam_volume = {{cvt|770|e3m3|abbr=on}} | spillway_count = 1 | spillway_type = [[Spillway#Types|Controlled and uncontrolled]] | spillway_capacity = {{unbulleted list|{{convert|245|m3/s|abbr=on}} chute on dam face|{{convert|190|m3/s|abbr=on}} valve in tunnel}} | res_name = [[Lake Burbury]]  | res_capacity_total = {{cvt|1081420|ML|acre.ft}} | res_capacity_active = {{cvt|1065000|ML|acre.ft}} | res_capacity_inactive= | res_catchment = {{cvt|559|km2}} | res_surface = {{cvt|5325|ha|acre}} | res_max_length = | res_max_width = | res_max_depth = | res_elevation = {{cvt|229|m}} {{AHD}} | res_tidal_range = | plant_name = [[John Butters Power Station]] | plant_coordinates = {{coord|42|09|21|S|145|32|04|E|type:landmark}} | plant_operator = Hydro Tasmania | plant_commission = {{start date|1992}} | plant_decommission = | plant_type = C | plant_hydraulic_head = {{cvt|184|m}} | plant_turbines = 1 x {{cvt|144|MW}}<br />[[Fuji Heavy Industries|Fuji]] [[Francis turbine|Frnacis-type]] | plant_capacity = {{cvt|144|MW}} | plant_capacity_factor= 0.9 | plant_annual_gen = {{cvt|576|GWh}} | website = {{URL|hydro.com.au/energy/our-power-stations/king-yolande|hydro.com.au}} | extra = <ref name=ANCOLD/> }}

The '''Crotty Dam''', also known during construction as the '''King Dam''',<ref>''King River Power Development'' [[Hydro Tasmania|Hydro-Electric Commission]] December 1983</ref> or the '''King River Dam''' on initial approval,<ref>{{cite journal |journal=Cross Currents |date=1983 |publisher=Hydro-Electric Commission |issn=0811-4803 |number=70 |title=Anthony and King Power Developments approved }}</ref> is a concrete-faced rockfill [[embankment dam]] across the [[King River (Tasmania)|King River]], between [[Mount Jukes, Tasmania|Mount Jukes]] and [[Mount Huxley, Tasmania|Mount Huxley]], located in the [[West Coast Tasmania|West Coast]] region of [[Tasmania]], Australia. Completed in 1991, the resultant [[reservoir]], [[Lake Burbury]], was established for the purpose of generating [[hydro-electricity|hydro-electric power]] via the '''John Butters Power Station'''. The dam, its reservoir, and the power station are owned and operated by [[Hydro Tasmania]].

== Dam and reservoir overview == === History === In the 1910s the [[Mount Lyell Mining & Railway Company]] had investigated and surveyed a site very close to this dam for a proposed hydro electric scheme.<ref>{{cite book |author-link=Geoffrey Blainey |last=Blainey |first=Geoffrey |title=The Peaks of Lyell |edition=6th |publisher=St. David's Park Publishing |location=Hobart |year=2000 |isbn=978-0-7246-2265-8 |title-link=The Peaks of Lyell |page=253 |quote=The early survey of Huntley Clarke at the King near the confluence with the Tofft River, and also at the head of the King river gorge between Mount Owen and Mount Huxley. }}</ref> [[Charles Whitham]] also wrote of the inevitability of the dam in 1927 and even proposed "Lake Dorothy" as a name for the reservoir.<ref name=Whitham/><ref name=Felton>{{cite book |author=Felton, Heather |title=Tickleberry Tales and Other Stories from the People of the Hydro |publisher=Hydro Tasmania |location=Tasmania, Australia |year=2007 |isbn=978-0-646-47724-4 }}</ref>{{rp|482, 465–472}}

Construction of the dam commenced in the 1980s following the [[Franklin Dam controversy]], and the reservoir was flooded in 1991. The dam was named in honour of [[James Crotty (prospector)|James Crotty]] who founded the North Mount Lyell Copper Mine at the turn of the 20th century. A ghost town site of the eponymous [[Crotty, Tasmania|Crotty]] was submerged by the waters of Lake Burbury; as was the settlement of [[Darwin, Tasmania|Darwin]].

=== Technical details === The Crotty Dam, together with the [[Darwin Dam]], are two major dams that form the headwaters for the King River Hydroelectric Power Development. The dam is located in the upper reaches of the King River gorge where the river breaks through the [[West Coast Range]]. It captures the high rainfall in the catchment of the King River and allows diversion of water through a tunnel to the John Butters Power Station downstream of the dam.

The concrete-faced [[rock-filled dam]] wall is {{convert|83|m}} high and {{convert|245|m}} long. When full, Lake Burbury has capacity of {{convert|1081420|ML|acre.ft}} and covers {{convert|53250|ha}}, draw from a [[drainage basin|catchment area]] of {{convert|559|km2}}. The single [[spillway#Types|controlled and uncontrolled spillway]] is capable of discharging {{convert|435|m3/s}}.<ref name=ANCOLD>{{cite web |title=Register of Large Dams Australia-2015 |date=January 2022 |access-date=2026-03-05 |url=https://ancold.org.au/information-resources/dams-information/ |work=[[ANCOLD]] |format=[[Microsoft Excel|Excel]]. Requires download. Row 135}}</ref>

==== Spillway ==== The spillway is located on the embankment, rather than on one of the rock abutments. This unique spillway approach had never been successfully attempted before in the design of dams of any significant height, due to problems in making allowance for embankment settlements. In the case of the Crotty Dam, the embankment was partly composed of well graded gravels, and thus a very high modulus of embankment deformation was achieved. The high modulus limits embankment settlements. Additionally, the spillway was designed to articulate in order to accommodate any settlement that ''did'' occur and to allow sufficient time for a large jet flow valve located in the diversion tunnel to be opened so that larger floods can be safely handled.

The spillway designers, Sergio Giudici, also the chief engineer on the [[Gordon Dam]], Frank Kinstler, Steven Li, Tony Morse and Graeme Maher were acknowledged within the engineering community because the spillway was the first known to provide for articulation of the spillway structure so that movements in its foundations could occur without damage to the overlying structure.<ref name=ea>{{cite web |url=https://www.engineersaustralia.org.au/portal/system/files/engineering-heritage-australia/nomination-title/Crotty_Dam.pdf |title=Crotty Dam, Tasmania |work=Submission for historic engineering marker |publisher=[[Engineers Australia]] |date=September 2000 }}</ref> In 2001, [[Engineers Australia]] selected Crotty Dam as one of the 25 dams with the greatest Australian heritage value and it was awarded a Historic Engineering Marker as part of the [[Engineers Australia#Engineering Heritage Recognition Program|Engineering Heritage Recognition Program]].<ref>{{cite web |url=https://portal.engineersaustralia.org.au/heritage/crotty-dam-king-river-1991 |title=Crotty Dam, King River, 1991- |publisher=Engineers Australia |date=2001 |access-date=2020-04-27}}</ref>

=== Reservoir === [[File:Lake Burbury.jpg|thumb|Looking north across the reservoir, from Bradshaw Bridge]] Named in honour of [[Stanley Burbury]], a former [[Governor of Tasmania]],<ref name=Whitham>{{cite book |author-link=Charles Whitham |last=Whitham |first=Charles |title=Western Tasmania – A land of riches and beauty |edition=Reprint 2003 |publisher=Municipality of Queenstown |location=Queenstown |year=2003 |page= }}</ref> Lake Burbury is fed mainly by rivers from the north, including the upper King, Nelson, Princess, and Eldon rivers that drain the [[West Coast Range (Tasmania)|West Coast Range]] and include the [[Linda Valley]].<ref name="map8013">{{cite map |title=Franklin: Sheet 8013 |work=Tasmania |scale=1:100,000 |edition=6th |year=1997 |quote=The smaller rivers on the eastern shore include the Princess River, Nelson River; to the west the Comstock Creek flows in from the valley between Mount Lyell and Mount Sedgwick. }}</ref> A natural lake, known as [[Lake Beatrice]], lies just north of the reservoir's northern shore which is below the eastern end of [[Mount Sedgwick (Tasmania)|Mount Sedgwick]]. Part of the reservoir is crossed by the Bradshaw Bridge{{efn|Named after the family that owned and operated the sawmill that was inundated at Princess River.}} to connect with the [[Lyell Highway]].

When it was impounded, the historical sites of Crotty and Darwin were flooded, the bridge of the [[North Mount Lyell Railway]] over the King River was not salvaged, and significant portions of the [[Kelly Basin Road]] were inundated. The dam and its reservoir were identified as "indicative places" on the (now defunct) [[Register of the National Estate]].<ref>{{cite AHD|101584|Crotty Dam and Lake Burbury, Lyell Hwy, Gormanston, TAS, Australia|access-date=24 May 2018}}</ref>

==== Recreation ==== [[File:Lake B regs.JPG|thumb|A regulation sign at the reservoir]] The reservoir is popular for fishing and anglers should be aware that the area is susceptible to extreme weather. A [[webcam]] is located on the south east shore of the lake which looks across to where the Lyell Highway emerges from the Linda Valley and moves south around the eastern base of [[Mount Owen (Tasmania)|Mount Owen]] and vision of fishing conditions may be viewed remotely.<ref>{{cite web |url=http://anglersalliance.org.au/web-cams/lake-burbury-webcam/ |title=Lake Burbury webcam |work=Anglers Alliance Tasmania |date= |access-date= }}</ref>

The reservoir lies to the west of the [[Franklin-Gordon Wild Rivers National Park]] and has a series of buffer zone conservation areas; the Princess River Conservation Area and the Crotty Conservation Area on the east shore, and the West Coast Range Regional Reserve on the west. Access to the reservoir's shore is limited below {{convert|242|m}} {{AHD}}, which is above the full supply level of {{convert|235|m}} {{AHD}}. Access is also restricted on the island created by the impoundment.<ref name="map8013"/><ref>{{cite map |publisher=[[Tasmap]] |title=Owen: 3833 |scale=1:25,000 |edition=2 |date=2001 }}</ref>

== Hydroelectric power station == The John Butters Power Station was commissioned by the [[Hydro Tasmania|Hydro Electric Commission (TAS)]] in 1992 as part of the [[King River (Tasmania)|King]]{{spaced endash}}[[Yolande River]] Power Scheme that comprises three hydroelectric power stations. Located {{convert|8|km}} below the dam wall, near the King River [[confluence]] with the [[Queen River, Tasmania|Queen River]],<ref name=Trove>{{cite book |title=King River power development |date=1992 |publisher=Hydro-Electric Commission |url=https://trove.nla.gov.au/work/34943188 |access-date=9 June 2018 |pages=10-13 |via=Trove. [[National Library of Australia]] }}</ref><ref>{{cite web |url=http://www.hydro.com.au/energy/our-power-stations/king-yolande |title=King - Yolande |work=Energy: Our power stations |publisher=[[Hydro Tasmania]] |access-date=21 June 2015 }}</ref><ref name=EHA>{{cite web |url=https://engineersaustralia.org.au/sites/default/files/2022-06/eha-magazine-v1-6.pdf |title=The Hydro after 100 Years |work=[[EHA Magazine]] |date=March 2015 |page=19 |access-date= |archive-url=https://web.archive.org/web/20220821083524/https://engineersaustralia.org.au/sites/default/files/2022-06/eha-magazine-v1-6.pdf |archive-date=2022-08-21 }}</ref> the power station is fed by water from Lake Burbury, and to the south by Darwin Dam. Water flow to the station is via a long headrace tunnel from the Crotty Dam via a {{convert|6.5|km|mi|adj=mid|-long}} unlined headrace tunnel that runs through Mount Jukes, and a {{convert|500|m|ft|adj=mid|-long}} steel lined power tunnel.<ref name=hydrotech>{{cite web |url=https://www.hydro.com.au/docs/default-source/clean-energy/our-power-stations/power-station-fact-sheets/john-butters-power-station-fact-sheet.pdf?sfvrsn=8ecc9b28_2 |title=John Butters Power Station: Technical fact sheet |work=King - Yolande Catchment |publisher=[[Hydro Tasmania]] |access-date=18 June 2023 |archive-url=https://web.archive.org/web/20230617195556/https://www.hydro.com.au/docs/default-source/clean-energy/our-power-stations/power-station-fact-sheets/john-butters-power-station-fact-sheet.pdf?sfvrsn=8ecc9b28_2 |archive-date=17 June 2023 |url-status=live }}</ref>

Built by the HEC, it was one of the last power stations constructed before its disaggregation and transformation to Hydro Tasmania.<ref name=EHA/><ref name=lifeblood>{{cite book |author1=Lupton, Roger |title=Lifeblood: Tasmania's hydro power |year=1999 |publication-date=1999 |publisher=Focus Publications |isbn=978-1-875359-33-2 }}</ref>{{rp|327–347}} The station has one [[Subaru Corporation|Fuji]] [[Francis turbine|Francis]] [[Water turbine|turbines]] with a generating capacity of {{convert|144|MW}} of electricity. Within the station building, the turbine has a half embedded spiral casing controlled via a spherical rotary inlet valve and a vertical lift, gravity closed intake gate designed to cut off full flow. The station output, estimated to be {{convert|576|GWh|TJ|lk=on}} annually,<ref name=ANCOLD/> is fed to [[TasNetworks]]' transmission grid via a 13.8 k[[voltage|V]]/220 kV three-phase Fuji generator transformer to the outdoor switchyard.<ref name=hydrotech/>

The station is remotely controlled from the [[Sheffield, Tasmania|Sheffield]] Control Centre.<ref name=Trove/>

=== Etymology === The power station was named in honour of [[John Butters]], the first general manager and chief engineer of Hydro Tasmania.<ref name=Felton/>{{rp|16–17}}<ref name=lifeblood/>{{rp|34–49}} When the King power scheme was approved by the [[Tasmanian Government]] the name on hydro plans for the proposed power station at that time was the ''Newall Power station''.<ref>{{cite map |author1=Tasmania. Hydro-Electric Commission |title=King River power development |publication-date=1992 |publisher=Hydro-Electric Commission |url=https://trove.nla.gov.au/work/34943188 |access-date=10 June 2018 |pages=8-9 |quote=''Lake Burbury'' being an extract from TASMAP Franklin 1: 100 000: There is a ''Newall Spur'' off Mount Jukes, 3 km south east of the power station, as well as Newall Creek, and a former mining site ''Harris' Reward'' on ''Newall Creek''.}}</ref><ref>{{cite book |author1=How, Duncan |title=Historic mines of Western Tasmania : a walking guide | year=1992 |publication-date=1992 |publisher=Walk the West Publications |isbn=978-0-646-10651-9 |page=40 }}</ref><ref>{{cite web |url=https://www.engineersaustralia.org.au/portal/system/files/engineering-heritage-australia/nomination-title/Crotty_Dam.pdf |title=Crotty Dam, Tasmania |work=Submission for historic engineering marker |publisher=[[Engineers Australia]] |date=September 2000}}</ref>

== See also == {{stack|{{Portal|Renewable energy|Australia|Water}}}} * [[List of power stations in Tasmania]] * [[List of reservoirs and dams in Australia#Tasmania|List of reservoirs and dams in Tasmania]] * [[List of lakes of Australia#Tasmania|List of lakes in Tasmania]]

== Notes == {{noteslist}}

==References== {{reflist}}

==Further reading== * {{cite book |last=Rae |first=Lou |title=The Abt Railway and Railways of the Lyell region |publisher=[[Lou Rae]] |location=Sandy Bay |year=2001 |isbn=978-0-9592098-7-7 }} {{ISBN|0-9592098-7-5}}. * {{cite book |author=Whitham, Lindsay |title=Railways, Mines, Pubs and People and other historical research |publisher=Tasmanian Historical Research Association |location=Sandy Bay |year=2002 |isbn=0-909479-21-6 }}

==External links== * {{commons category-inline|Crotty Dam}} ** {{commons category-inline|Lake Burbury, Tasmania}} * {{cite web |url=http://www.hydro.com.au/home/Tourism+and+Recreation/King+Catchment/ |title=King Catchment |work=[[Hydro Tasmania]] |date= |access-date= |archive-date=2006-09-18 |archive-url=https://web.archive.org/web/20060918150455/http://www.hydro.com.au/home/Tourism+and+Recreation/King+Catchment/ }} * {{cite web |url=http://www.hydro.com.au/energy/our-power-stations/king-yolande-0 |title=Our power stations: King-Yolande |work=[[Hydro Tasmania]] |date= |access-date= }}{{dead link|date=December 2017 |bot=InternetArchiveBot |fix-attempted=yes }}

[[Category:1991 establishments in Australia]] [[Category:Concrete-face rock-fill dams]] [[Category:Dams completed in 1991]] [[Category:Energy infrastructure completed in 1992]] [[Category:Hydroelectric power stations in Tasmania]] [[Category:Hydro Tasmania dams]] [[Category:King River power development scheme]] [[Category:Recipients of Engineers Australia engineering heritage markers]] [[Category:Reservoirs in Tasmania|Burbury]] [[Category:West Coast Range]]