Scrivener Dam is a concrete

gravity dam A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation to oppose the horizontal pressure of water pushing against it. ...

that impounds the

Molonglo River The Molonglo River, a perennial river that is part of the Murrumbidgee catchment within the Murray–Darling basin, is located in the Monaro and Capital Country regions of New South Wales and the Australian Capital Territory, in Australia. Lo ...

Canberra, Australian Capital Territory Canberra ( ) is the capital city of Australia. Founded following the Federation of Australia, federation of the colonies of Australia as the seat of government for the new nation, it is Australia's largest inland city and the List of citi ...

. The dam creates

Lake Burley Griffin Lake Burley Griffin is an artificial lake in the centre of Canberra, the capital of Australia. It was completed in 1963 after the Molonglo River, which ran between the city centre and Parliamentary Triangle, was dammed. It is named after Walte ...

, which was established for recreational and ornamental purposes. Named in honour of surveyor

Charles Scrivener Charles Robert Scrivener (2 November 1855 – 26 September 1923) was an Australian surveyor, and the person who surveyed numerous sites in New South Wales for the selection of a site for the Australian Capital Territory and Australia's capital ...

, the dam was officially

inaugurated In government and politics, inauguration is the process of swearing a person into office and thus making that person the incumbent. Such an inauguration commonly occurs through a formal ceremony or special event, which may also include an inaugu ...

on and the official filling of the lake commemorated on by the

Prime Minister A prime minister, premier or chief of cabinet is the head of the cabinet and the leader of the ministers in the executive branch of government, often in a parliamentary or semi-presidential system. Under those systems, a prime minister is not ...

Robert Menzies The name Robert is an ancient Germanic given name, from Proto-Germanic "fame" and "bright" (''Hrōþiberhtaz''). Compare Old Dutch ''Robrecht'' and Old High German ''Hrodebert'' (a compound of ''Hrōþ, Hruod'' ( non, Hróðr) "fame, glory ...

. The dam wall is located on Lady Denman Drive and is adjacent to the

National Zoo & Aquarium The National Zoo and Aquarium is a privately owned zoo and aquarium in the Australian capital city of Canberra. It is located in Yarralumla at the western end of Lake Burley Griffin, next to Scrivener Dam. It recently had a major expansion, wi ...

and a viewing area for the

official residence An official residence is the House, residence of a head of state, head of government, governor, Clergy, religious leader, leaders of international organizations, or other senior figure. It may be the same place where they conduct their work-relate ...

of the

Governor-General of Australia The governor-general of Australia is the representative of the monarch, currently King Charles III, in Australia. Scrivener Dam, designed in

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

, holds back the waters of the Molonglo River within Lake Burley Griffin. About of

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...

was used in the construction of the dam wall. The dam is high and long with a maximum wall thickness of . The dam is designed to handle a once in 5,000 year flood event. It utilised state-of-the-art post-tensioning techniques to cope with any problems or movements in the riverbed. The dam has five bay

spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure tha ...

s controlled by wide,

hydraulically Hydraulics (from Greek language, Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is th ...

operated fish-belly flap gates. Hinge anchors support the flap gates; with six hinges per gate, and four anchors per hinge. 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. 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.

Dam maintenance

The

National Capital Authority The National Capital Authority (NCA) is a statutory authority of the Australian Government that was established to manage the Commonwealth's interest in the planning and development of Canberra as the capital city of Australia. Timeline of th ...

, a

statutory authority A statutory body or statutory authority is a body set up by law (statute) that is authorised to implement certain legislation on behalf of the relevant country or state, sometimes by being Primary and secondary legislation, empowered or deleg ...

of the

Australian Government The Australian Government, also known as the Commonwealth Government, is the national government of Australia, a federal parliamentary constitutional monarchy. Like other Westminster-style systems of government, the Australian Government i ...

, is responsible for the administration and oversight of Scrivener Dam, as the dam lies within the ''Designated Area'', under the . The Authority manages external contractors to deliver services that are competitively tendered. 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 in diameter and long. It was anticipated that work would be completed by the end of 2013, and cost A$20m.

Flood mitigation

Scrivener Dam is operated in an environment that minimises flooding of the environs of Lake Burley Griffin. Flows of 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 , measured at the East Basin. With three sluice valves open, outflows of can be achieved through either automatic or manual operation of the dam. A minimum base flow of is required in the Molonglo River, downstream of Scrivener Dam at the gauging station below Coppins Crossing.

History

Lake filling

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 Sir Gordon Freeth, KBE (6 August 191427 November 2001) was an Australian politician and diplomat. He served in the House of Representatives from 1949 to 1969, including as a minister in the Coalition governments from 1958 to 1969. He lat ...

; 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. 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. The dam, together with Lake Burley Griffin and adjacent lands, is listed on the

Register of the National Estate The Register of the National Estate was a heritage register that listed natural and cultural heritage places in Australia that was closed in 2007. Phasing out began in 2003, when the Australian National Heritage List and the Commonwealth Heritag ...

, a listing of places of significant natural and cultural heritage. Since 2012, the register has frozen.

References

External links