Scrivener Dam

File:Scrivener Dam with 3 open sluices.jpg, 2010]]

Scrivener Dam, designed in Germany,{{Cite book |title=Canberra 1954-1980 |first=Eric |last=Sparke |year=1988 |publisher=Australian Government Publishing Service |isbn=0-644-08060-4 |page=138 }} holds back the waters of the Molonglo River within Lake Burley Griffin. About {{convert|55000|m3}} of concrete was used in the construction of the dam wall. The dam is {{convert|33|m}} high and {{convert|319|m}} long with a maximum wall thickness of {{convert|19.7|m}}. The dam is designed to handle a once in 5,000 year flood event.{{cite web |url=http://www.nationalcapital.gov.au/index.php?option=com_content&view=article&id=254:fact-sheets&catid=60:links-education&Itemid=248#20 |title=Scrivener Dam |work=Education Fact Sheets |publisher=National Capital Authority |date=9 November 2010 |access-date=16 February 2013 }}

It utilised state-of-the-art post-tensioning techniques to cope with any problems or movements in the riverbed.{{Cite book |author=Sparke |page=136 |title=Canberra 1954-1980 }}

The dam has five bay spillways controlled by {{convert|30.5|m}} wide, hydraulically operated fish-belly flap gates. Hinge anchors support the flap gates; with six hinges per gate, and four anchors per hinge.{{cite web |url=http://www.nationalcapital.gov.au/index.php?option=com_content&view=article&id=2193%3Ascrivener-dam-question-and-answer&catid=59%3Alinks-national-land-a-lake&Itemid=1 |title=Scrivener Dam Question and Answer |author=Fortunato, Pedro |publisher=National Capital Authority |date=1 December 2011 |access-date=16 February 2013 }} The fish-belly gates allow for a precise control of water level, reducing the dead area on the banks between high and low water levels. As at November 2010, the five gates have only been opened simultaneously once in the dam's history, during heavy flooding in 1976.

The dam wall provides a crossing for the lake and consists of a roadway, called Lady Denman Drive, and a bicycle path.{{cite book |title=Lake Burley Griffin, Canberra: Policy Plan |page=9 }} The roadway was possible because the dam gates are closed by pushing up from below, unlike most previous designs that wherein the gates were lifted from above.{{Cite book |author=Sparke |page=140 |title=Canberra 1954-1980 }}

File:Repair spare dam gate.JPG Lake Burley Griffin Canberra]]

The National Capital Authority, a statutory authority of the Australian Government, is responsible for the administration and oversight of Scrivener Dam, as the dam lies within the Designated Area, under the {{Cite Legislation AU|Cth|act||Australian Capital Territory (Planning and Land Management) Act, 1988}}. The Authority manages external contractors to deliver services that are competitively tendered.{{cite web |url=http://www.nationalcapital.gov.au/index.php?option=com_content&view=article&id=314&Itemid=283 |title=Maintenance and Operation of Assets |work=National Land & Lake |publisher=National Capital Authority |date=3 July 2012 |access-date=16 February 2013 }}{{cite web |url=http://www.nationalcapital.gov.au/index.php?option=com_content&view=article&id=1256%3Aappendix-j&catid=95%3Anational-capital-plan&Itemid=167 |title=Lake Burley Griffin Technical and Management Guidelines |work=About us |publisher=National Capital Authority |date=26 May 2010 |access-date=16 February 2013 }}

A routine annual audit of the dam wall undertaken during 2011 revealed that the anchor bolts, which are part of the flap gate hinge mechanism, showed signs of corrosion. These bolts, of which there are 120 in total, are each {{convert|50|mm}} in diameter and {{convert|2|m}} long. It was anticipated that work would be completed by the end of 2013, and cost A$20m.{{cite news |date=1 December 2011 |title=Scrivener Dam needs $20m repair |url=http://www.canberratimes.com.au/act-news/scrivener-dam-needs-20m-repair-20111201-1uuk5.html |work=The Canberra Times |access-date=16 February 2013 }}{{cite news |url=http://www.abc.net.au/news/2011-12-01/scrivener-dam-repair-bill/3706644 |title=$20m to fix Scrivener Dam |date=1 December 2011 |publisher=ABC News|location=Australia |access-date=16 February 2013 }}

Scrivener Dam is operated in an environment that minimises flooding of the environs of Lake Burley Griffin. Flows of {{convert|2000|m3/s|abbr=on}} and above at the dam spillway are achieved with all five flap gates open and are able to maintain the normal level of the Lake at {{convert|555.93|m}}, measured at the East Basin. With three sluice valves open, outflows of {{convert|55|m3/s|abbr=on}} can be achieved through either automatic or manual operation of the dam. A minimum base flow of {{convert|0.03|m3/s|abbr=on}} is required in the Molonglo River, downstream of Scrivener Dam at the gauging station below Coppins Crossing.

{{see also|History of Lake Burley Griffin}}

File:Lights of the Scrivener Dam.jpg

A prolonged drought coincided with and eased work on the lake's construction. The valves on the Scrivener Dam were closed on 20 September 1963 by Interior Minister Gordon Freeth; Prime Minister Menzies was absent due to ill health. Several months on, with no rain in sight, mosquito-infested pools of water were the only visible sign of the lake filling. With the eventual breaking of the drought and several days of heavy rain, the lake filled, and reached the planned level on 29 April 1964.

On 17 October 1964, Menzies commemorated the filling of the lake and the completion of stage one with an opening ceremony amid the backdrop of sailing craft.{{Cite web |url=http://www.menziesvirtualmuseum.org.au/1960s/1964.html |title=Menzies Virtual Museum |publisher=Menzies Virtual Museum |year=1964 |access-date=3 February 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090119074739/http://www.menziesvirtualmuseum.org.au/1960s/1964.html |archive-date=19 January 2009 }} This was accompanied by fireworks display, and Griffin's lake had finally come to fruition after five decades, at the cost of A$5,039,050.{{Cite book |author=Sparke |page=141 |title=Canberra 1954-1980 }}

The dam, together with Lake Burley Griffin and adjacent lands, is listed on the Register of the National Estate, a listing of places of significant natural and cultural heritage. Since 2012, the register has frozen.{{cite web |url=http://www.environment.gov.au/heritage/places/rne/index.html |title=Register of the National Estate - archive |work=Department of Sustainability, Environment, Water, Population and Communities |publisher=Commonwealth of Australia |date=17 February 2012 |access-date=16 February 2013 }}{{cite web |url=http://www.environment.gov.au/heritage/publications/pubs/priority-assessment-chl-2010-11.rtf |title=Finalised Priority Assessment List for the Commonwealth Heritage List for 2010-2011 |work=Department of Sustainability, Environment, Water, Population and Communities |publisher=Commonwealth of Australia |date=30 June 2012 |access-date=16 February 2013 }}

{{Portal|Australia}}

• History of Canberra
• History of Lake Burley Griffin

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• [http://www.nationalcapital.gov.au/index.php?option=com_content&view=category&id=76&Itemid=317 Lake Water Quality Updates] includes current water level

{{Lake Burley Griffin}}

{{Canberra landmarks}}

{{Rivers of the Australian Capital Territory}}

Category:Buildings and structures in Canberra

Category:Dams completed in 1963

Category:Gravity dams

Category:Murray-Darling basin

Category:Dams in the Australian Capital Territory