Wivenhoe Dam
{{Use Australian English|date=June 2020}}
{{Use dmy dates|date=August 2014}}
{{Infobox dam
| name = Wivenhoe Dam
| name_official =
| image = Aerial photograph of Wivenhoe Dam, Split Card Creek and picnic area, 11 September 1985.jpg
| image_size = 250
| image_caption = Wivenhoe Dam, wall, and spillway, 1985
| image_alt =
| location_map = Queensland
| location_map_size =
| location_map_caption = Location of the Wivenhoe Dam in Queensland
| coordinates = {{coord|27|23|38|S|152|36|28|E|type:landmark|display=inline,title}}
| country = Australia
| location = South East Queensland
| purpose = {{unbulleted list|Potable water supply|Flood mitigation|Hydroelectricity|Recreation}}
| status = O
| construction_began = {{start date and age|df=yes|1973|03|br=y}}
| opening = {{start date and age|1984}}
| demolished =
| cost =
| owner =
| operator = SEQ Water
| dam_type = E
| dam_length = {{Convert|2300|m|abbr=on}}
| dam_height = {{Convert|59|m|abbr=on}}
| dam_height_thalweg = {{convert|23|m|abbr=on}} {{AHD}}
| dam_width_crest =
| dam_width_base =
| dam_elevation_crest = {{convert|79|m|abbr=on}} {{AHD}}
| dam_volume = {{Convert|4140|e3m3||abbr=on}}
| dam_crosses = Brisbane River
| spillway_count = 2
| spillway_type = {{unbulleted list|Service, controlled crest-overflow|Auxiliary}}
| spillway_capacity = {{convert|12000|m3/s|abbr=on}}
| res_name = Wivenhoe Reservoir
| res_capacity_total = {{convert|1165238|ML|e6impgal+e6USgal|abbr=on}}
| res_catchment = {{Convert|7020|km2|abbr=on}}
| res_surface = {{Convert|109.4|km2|abbr=on}}
| res_max_depth =
| res_tidal_range =
| plant_name = Wivenhoe Power Station
| plant_operator = Tarong Energy
| plant_commission = May 1984
| plant_decommission =
| plant_type =Pumped-storage
| plant_turbines = 2
| plant_capacity = {{convert|500|MW|abbr=on}}
| plant_annual_gen =
| website = {{url|http://www.seqwater.com.au/water-supply/dam-operations/wivenhoe-dam|www.seqwater.com.au}}
| extra =
}}
Wivenhoe Dam is a rock and earth-fill embankment dam with a concrete spillway across the Brisbane River in South East Queensland, Australia. The dam takes it names from the local Wivenhoe Pocket rural community. The dam wall is located about {{convert|80|km|mi|}} by road from the centre of Brisbane. The primary purpose of the dam is the supply of potable water for the Brisbane and Ipswich regions. South-east Queensland's largest dam also provides for flood mitigation control, hydroelectricity, and recreation.{{cite web|url=http://www.ancold.org.au/wp-content/uploads/2012/10/Dams-Australia-2010-v1-for-website.xls|format=Excel (requires download)|title=Register of Large Dams in Australia|publisher=Australian National Committee on Large Dams|year=2010|access-date=5 July 2014|work=Dams information|archive-date=12 December 2013|archive-url=https://web.archive.org/web/20131212120804/http://www.ancold.org.au/wp-content/uploads/2012/10/Dams-Australia-2010-v1-for-website.xls|url-status=dead}} The impounded reservoir is called Lake Wivenhoe and the dam, the lake and a narrow strip of surrounding land forms a locality also called Lake Wivenhoe.
Wivenhoe Dam was planned in the early 1970s. The 1974 Brisbane flood highlighted the need for flood protection for South East Queensland.{{cite web|title=Wivenhoe and Somerset Dams|url=http://www.cabinet.qld.gov.au/MMS/MediaAttachments/2010/pdf/32253%20SEQWG%20Wivenhoe%20Fact%20Sheet%20A4%202pp%20F.pdf|work=SEQ Water Grid|publisher=The Queensland Cabinet and Ministerial Directory|access-date=13 January 2011}} The lake also forms part of the water storages for the Wivenhoe Power Station.
Location and features
File:Wivenhoe Dam and spillway, August 2020, 01.jpg
The earth and rock dam structure is {{convert|59|m}} high and {{convert|2300|m}} long. The {{convert|4140|e3m3|adj=on}} dam wall holds back the {{convert|1165000|ML|e9impgal+e9USgal|adj=on}} reservoir when at full capacity. From a catchment area of {{convert|7020|km2}} that includes much of the south{{endash}}western slopes of the D'Aguilar National Park, the dam creates Lake Wivenhoe, with a surface area of {{convert|1094|ha|acre}}, a maximum shoreline of {{convert|462|km}}, and an average annual evaporation level of {{convert|1872|mm|abbr=on}}. The gated spillway, with five steel crest gates that are {{convert|12|m}} wide and {{convert|16.6|m}} high, has a discharge capacity of {{convert|12000|m3/s}}. The dam also has an auxiliary spillway to stop over-topping. The dam is managed by SEQ Water since July 2008 when most dam assets were transferred to the statutory authority, as part of a water security project in the South East Queensland region, known as the South East Queensland Water Grid.{{cite web |url=http://www.baysidebulletin.com.au/news/local/news/political/water-funds-slash-debt/805745.aspx|title=Water funds slash debt |author=Hurst, Daniel|access-date=21 April 2008|date=7 July 2009|work=The Bayside Bulletin}}
=Construction=
Wivenhoe was initially investigated for a dam site in the 1890s and again in 1933.Queensland Environmental Protection Agency, Heritage Trails of the Great South East, State of Queensland, 2000 {{ISBN|0-7345-1008-X}} Further investigations into a dam began in the mid 1960s. In November 1971, Government approval was given to proceed with construction. Acquisition of lands of the submerged portion of the dam began in March 1973. In 1976, the Government gave approval to proceed with construction of the pumped storage hydro-electric scheme. Total cost for the hydro-electric project was A$450 million. In March 1977, the first construction contract was awarded.{{cite book |title=The History of Electricity in Queensland |last=Dunn |first=Col |year=1985 |publisher=Col Dunn |location=Bundaberg |isbn=0-9589229-0-X |pages=171 }} The dam was designed by the Queensland Water Resources Commission.
In June 1983, the partially completed dam mitigated a potentially severe flood that may have caused damage equal to the 1893 Brisbane flood.{{cite book |title=Shaping a city |last=Cole |first=John R. |year=1984 |publisher=William Brooks Queensland |location=Albion, Queensland |isbn=0-85568-619-7 |pages=316 }} Construction work, carried out by Thiess Brothers, was complete by 1985.{{cite web|url=https://www.theconstructionindex.co.uk/news/view/thiess-barnard-jv-to-build-queensland-dam|title=Thiess Barnard JV to build Queensland dam|date=1 December 2011|publisher=Construction Index|access-date=3 January 2020}} To provide the {{convert|337.5|km2|sqmi|}} of land required for the dam, 200 properties were acquired. The catchment area has an average annual rainfall of {{convert|940|mm}}. The dam holds twice as much water as Sydney Harbour and can hold about seven times more water than the Hinze Dam on the Gold Coast. Wivenhoe Dam contributes to the Gold Coast's water supply.
=Purpose=
File:Wivenhoe Dam Flood release 2010.jpg
The dam was designed as a response to the floods that damaged Brisbane in 1974. Built in the late 1970s – early 1980s as a multifunction facility by a consortium of construction companies including Thiess Brothers, Wivenhoe Dam provides a safe water supply to the people of Brisbane and adjacent regions. Additionally, Wivenhoe Dam serves as the lower storage in a pumped-storage, hydro-electric generating facility, the Wivenhoe Power Station. The upper reservoir is formed by Splityard Creek Dam, of earth and rock construction, with a capacity of {{convert|28700|ML|e3impgal+e3USgal}}. Under normal conditions the dam supplies water via pipeline to both Tarong Power Station and Tarong North Power Station, but during drought conditions only supplies water to Tarong North.
==Flood mitigation==
File:Wivenhoe Spillway 2011.jpg
During a flood the dam is designed to hold back {{convert|1.967|e6ML|e6impgal+e6USgal}} https://www.seqwater.com.au/sites/default/files/2019-09/Fact%20sheet%20-%20About%20Wivenhoe%20Dam.pdf of additional water for flood mitigation or 225% capacity. Under the water release plan which is defined by law, excess water must be released from the dam within seven days or a week of it reaching 100% capacity.{{Cite news |url=http://www.news.com.au/national/parts-of-brisbane-set-to-flood-as-water-released-from-wivenhoe-dam-combines-with-high-tide/story-e6frfkvr-1225938466703|title=Parts of Brisbane set to flood as water released from Wivenhoe Dam combines with high tide |author1=Heger, Ursula|author2=Caldwell, Anna|access-date=17 October 2010|date=14 October 2010|work=The Courier-Mail|location=Queensland }} In February 1999, the level reached 135% of full capacity.{{cite journal |last1=Smith |first1=Ian |last2=McAlpine |first2=Clive |date=2014 |title=Estimating future changes in flood risk: Case study of the Brisbane River, Australia |journal=Climate Risk Management |volume=6 |pages=6–17 |doi=10.1016/j.crm.2014.11.002 |bibcode=2014CliRM...6....6S |doi-access=free }} Between April 2004 and September 2008, a {{convert|165|m|adj=on}} wide auxiliary spillway with a three-bay fuse plug was installed on the western portion of the dam to further mitigate flooding.{{cite web|title=In-Congress Technical Tours|url=http://www.iahr2011.org/in-congress-technical-tours.php|publisher=International Association for Hydro-Environment Engineering and Research|access-date=12 January 2011|archive-date=30 May 2011|archive-url=https://web.archive.org/web/20110530023641/http://www.iahr2011.org/in-congress-technical-tours.php|url-status=dead}} In 2007, a feasibility study concluded that Wivenhoe Dam failed to satisfy the Australian National Committee on Large Dams (ANCOLD) guidelines on acceptable flood capacity.
== 2000–2007 drought==
Brisbane water levels reduced to under 20% of capacity, having had no substantial inflow for five years.{{cite web | url=http://www.seqwater.com.au/water-supply/dam-levels | title=Dam Levels}}
===2011 Queensland floods===
{{main|2010–2011 Queensland floods}}
The largest ever recorded inflows for the dam occurred in January 2011.{{Cite news |url=http://www.brisbanetimes.com.au/environment/weather/bom-keeps-mum-on-january-forecast-flaws-20110308-1blkk.html|title=BoM keeps mum on January forecast flaws|access-date=10 March 2011|date=8 March 2011|work=Brisbane Times}} On 11 January 2011, Wivenhoe Dam reached its highest level ever, 191% of normal water supply storage capacity, as it held back floodwater.{{Cite news|url=http://news.ninemsn.com.au/national/floods/8195758/controlled-releases-at-wivenhoe-cut|title=Controlled releases at Wivenhoe cut|access-date=12 January 2011|date=12 January 2011|work=Nine News|archive-date=5 April 2012|archive-url=https://web.archive.org/web/20120405103714/http://news.ninemsn.com.au/national/floods/8195758/controlled-releases-at-wivenhoe-cut|url-status=dead}} Because it is an embankment dam, it was not designed to spill over its crest or overtop and there is a risk that if waters spilled over the crest, this could erode the dam wall and potentially cause the dam to fail. In this scenario the water level would need to rise to 225% capacity. To prevent this, the dam was designed and built to include a second emergency spillway.{{Cite news|url=http://www.abc.net.au/news/stories/2011/01/11/3110758.htm|archive-url=https://web.archive.org/web/20110112202628/http://www.abc.net.au/news/stories/2011/01/11/3110758.htm|url-status=dead|archive-date=12 January 2011|title=Wivenhoe put to the ultimate test|author=Andersen, Brigid|access-date=11 January 2011|date=11 January 2011|work=ABC New|location=Australia}} During the peak of the flooding event the dam water level reached {{convert|60|cm}} below the auxiliary spillway height.{{Cite news|url=http://www.theaustralian.com.au/news/nation/engineers-reduce-dam-flow/story-e6frg6nf-1225986634232|title=Engineers reduce dam flow |author=Callinan, Rory|access-date=14 January 2011|date=13 January 2011|newspaper=The Australian }}
===2022 eastern Australia floods===
{{main|2022 eastern Australia floods}}
Wivenhoe Dam reaches a 180% capacity as of 27 February 2022{{Cite web |title=seqwater, historic dam levels |url=https://www.seqwater.com.au/historic-dam-levels |access-date=2022-11-17 |website=www.seqwater.com.au}}
=Recycled water=
File:Wivenhoe Dam Spillway Open Video.ogv
In 2006, emergency plans for placing fully treated recycled water from the Western Corridor Recycled Water Scheme into the dam to supplement supply were made public. Sixty million litres of recycled water were to be pumped into the dam by early 2009.{{Cite news |url=http://www.couriermail.com.au/news/queensland/warning-over-recycled-water/story-e6freoof-1111117991202 |title=Warning over recycled water |author=Greg Roberts |access-date=21 September 2010 |date=9 November 2008 |work=The Courier-Mail |publisher=Queensland Newspapers }} Increasing rainfall from 2008 resulted in the plan for recycled water to enter the region's drinking water supply to be postponed.
=Recreation=
Lake Wivenhoe is also a camping and outdoor recreation destination. Camping sites are provided at Captain Logan and Lumley Hill Areas.{{Cite web |url=http://www.somerset.qld.gov.au/lakes-somerset-wivenhoe-and-atkinson |title=Lakes – Somerset, Wivenhoe and Atkinson |access-date=21 September 2010 |publisher=Somerset Regional Council |archive-date=22 January 2011 |archive-url=https://web.archive.org/web/20110122213533/http://www.somerset.qld.gov.au/lakes-somerset-wivenhoe-and-atkinson |url-status=dead }} The managed camping facilities at Captain Logan Camp include hot showers, barbecues and toilets, and are adjacent to playgrounds and a boat ramp at Logan Inlet. Cormorant Bay, Hamon Cove and Spillway Common also have facilities for picnic.
A stocked impoundment permit is required to fish in the dam.{{cite web|url=http://www.daff.qld.gov.au/fisheries/recreational/permits-dams/stocked-impoundment-permit|title=Do I need a permit to go fishing in a dam?|work=Department of Agriculture, Fisheries and Forestry|publisher=Queensland Government|date=5 February 2013|access-date=5 July 2014}} Swimming is permitted and camp sites have been established. Electric and non-powered boating with a permit is allowed, but domestic animals are banned.{{Cite web |url=http://www.ourbrisbane.com/see-and-do/822276.lake-wivenhoe |title=Lake Wivenhoe |access-date=21 September 2010 |work=ourbrisbane.com |publisher=Brisbane City Council }}
==Fauna==
The dam is home to the endangered Australian lungfish.{{cite web|title=Australian Lungfish (Neoceratodus forsteri)|url=http://www.environment.gov.au/biodiversity/threatened/publications/lungfish.html|work=Department of Sustainability, Environment, Water, Population and Communities|access-date=14 January 2011|year=2003}} Anne Kemp, a researcher from the University of Queensland, estimates there was a population of 800 in 2010 but many are swept out of the dam when the spillway is opened{{cite web|title=Neoceratodus forsteri – Australian Lungfish, Queensland Lungfish|url=http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=67620|work=Department of Sustainability, Environment, Water, Population and Communities|access-date=14 January 2011}}{{cite web|title=Where lungfish are found|url=http://www.annekempslungfish.com/lungfish_habitat.html|work=Anne Kemps Lungfish|access-date=14 January 2011}} and that their food source of molluscs and clams is insufficient to maintain the lungfish in the dam.{{Cite news |url=http://www.brisbanetimes.com.au/environment/wivenhoe-lungfish-woes-follow-traveston-warnings-20101027-173z0.html |title=Wivenhoe lungfish woes follow Traveston warnings |author=Tony Moore |access-date=6 November 2010 |date=28 October 2010 |work=Brisbane Times |publisher=Fairfax Media }}
Self-sustaining populations of lungfish have lived in dams in South East Queensland for over 100 years since 1896. Lungfish were originally restricted to the Mary and Burnett river systems but due to perceived threats to their survival they were introduced to other rivers and dams, including the Brisbane River, in 1895–1896.{{cite web|title=The unique Australian Lungfish|url=http://www.qm.qld.gov.au/Find+out+about/Animals+of+Queensland/Fishes/The+unique+Australian+Lungfish|work=Queensland Museum|access-date=15 January 2011}}
This was done to improve the viability of the species.
Land around the dam has been the location for a tree planting program in order to provide koala habitat.{{cite web |url=https://statements.qld.gov.au/statements/94473 |title=153,000 trees planted at Wivenhoe Dam to increase koala habitat and water quality |last=Scanlon |first=Meaghan |date=15 February 2022 |publisher=Government of Queensland |access-date=21 September 2022 }} Planting will occur between 2020 and 2025.
See also
{{stack|{{Portal|Queensland|Water}}}}
References
{{Reflist|30em}}
External links
{{Commons category|Lake Wivenhoe}}
- [http://www.sweetwaterfishing.com.au/Wivenhoe.htm Lake Wivenhoe fishing information & map]
- [http://www.seqwater.com.au/water-supply/dam-operations/wivenhoe-dam SEQWater – Wivenhoe Dam]
{{South East Queensland}}
{{WaterQueensland |state=autocollapse}}
Category:Bridges over the Brisbane River
Category:Buildings and structures in Somerset Region
Category:1984 establishments in Australia