Lake Burley Griffin
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Lake Burley Griffin is a large lake in the centre of Canberra, Australia's federal capital city. It was created in 1963 after the Molonglo River, which runs through the city centre, was dammed. It is named after Walter Burley Griffin, the architect who won the design competition for the city of Canberra National Library of Australia lie on its shores, and Parliament House is a short distance away. Its surrounds are also quite popular with recreational users, particularly in the warmer months. Though swimming in the lake is uncommon, it is used for a wide variety of other activities, such as rowing, fishing, and sailing.
The lake's flow is regulated by the 33 metre tall Scrivener Dam, which is designed to handle a once in 5000 year flood event. In times of drought, water levels can fall below desired limits; so to compensate, water is released from the Googong Dam, located on a tributary of the Molonglo River.
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Design
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Charles Robert Scrivener (1855-1923) recommended the site for Canberra in 1909, and his detailed survey plans of the area were supplied to the architects who entered the Canberra design competition. Later, Scrivener, as part of a design committee, was responsible for modifying Griffin's winning designweirs. The new design included elements from several of the best design submissions and was widely criticised as being ugly. The new plan for the lake retained Griffin's three formal basins: east, central, and west, though in a more relaxed formmetres of water with a surface area of 6.64 km2). It is 11 kilometres long, 1.2 kilometres wide at its widest point, has a shoreline of 40.5 kilometres and a water level of 556 metres above sea levelAustralian National Carillon.
Construction
Excavation
Construction of Lake Burley Griffin was begun in 1960 and progressed well due to drought having greatly reduced the water flow of the Molonglo River. Critics believed that the lake would act as a breeding ground for mosquitoes. Care was taken to excavate the lake to a depth of over two metres both to prevent mosquitoes from breeding and to allow clearance for boat keels. The lake varies in depth from around 2 metres at the eastern end, to 18 metres at the dam wall. The mean depth is 4 metres.
Dam
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The dam used to create Lake Burley Griffin was named Scrivener Dam after Robert Charles Scrivener. The dam is 33 metres high and 319 metres long with a five bay spillway controlled by 30.5 metre wide, hydraulically operated fish-belly flap gates. 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. The five gates have only been opened simultaneously once in the dam's history, during flooding in 1976. The dam is designed to handle a once in 5000 year flood event. The dam contains 55,000 cubic metres of concrete with a maximum wall thickness of 19.7 metres. A roadway atop the dam wall provides a third road crossing for the lake.
Filling
Unfortunately the drought that had made construction easy meant that when the valves were closed on 20 September 1963 the lake was very slow to fill. After seven months there was still only a trickle of water and some mosquito-infested pools. Luckily the drought broke and the lake was filled after only several days of heavy rainOctober 17, 1964 Robert Menzies commemorated the filling of the lake and the completion of stage one with an opening ceremonyGordon Freeth suggested that Menzies had "been in a material sense the father of the lake" and that the lake should be named Lake Menzies. Menzies insisted that the lake should be named after Walter Burley Griffin—Canberra's designer responsible for the concept of the lake—who had no existing monument in Canberra. (Griffin usually referred to himself as Walter Griffin, but the form "Walter Burley Griffin" has become established in Australia.)
Lake levels in times of severe drought can sometimes fall below the desired level. This can be compensated for by the release of water from Googong Dam on the Queanbeyan River, a tributary of the Molonglo. Googong Dam was built in 1979 to cope with Canberra and Queanbeyan's growing water supply needs, and can contain up to 124,500 million litres of waterCommonwealth Avenue Bridge (310 metres), Kings Avenue Bridge (270 metres) and a roadway over Scrivener Dam. The two bridges were constructed before the lake was filled and are designed to allow the passage of recreational sailing boats with tall masts. Both bridges are dual-carriageway, Commonwealth Avenue has three lanes in each direction while Kings Avenue has two.
Scrivener Dam is crossed by Lady Denman Drive which has a narrow two lane roadway.
Captain Cook Memorial
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The Captain James Cook Memorial was built by the Commonwealth Government to commemorate the Bicentenary of Captain James Cook's first sighting of the east coast of Australia. The memorial includes a water jet located in the central basin and a skeleton globe sculpture at Regatta Point showing the paths of Cook's expeditions. On 25 April 1970, Queen Elizabeth II officially inaugurated the memorial.
The water jet is powered by two 560 kilowatt electric motors driving four stage centrifugal pumps capable of pumping up to 250 litres per second against a head of 183 meters. The water velocity at the water nozzle is 260 km/h. While running both pumps simultaneously the main jet throws approximately six tons of water into the air at any instant, reaching a maximum height of 147 metres. Alternatively the jet can be run on a single pump reaching a lower height of 110 metres. During special occasions it can be illuminated, often with coloured lights.
The water jet operates from 10-12 am in the morning and 2-4 pm in the afternoon. During summer it also operates for an extra period from 7-9 pm. In periods of high wind the jet is automatically disabled as water landing on the nearby Commonwealth Avenue Bridge can be a hazard to traffic. The water jet must also be occasionally shut down when drought lowers the water level of the lakeToxic blue-green algae blooms are unfortunately a reasonably common occurrence in the lake. Warnings about coming into contact with the water are released when an algal bloom is detected. Attempts are being made to limit the amount of phosphates entering the lake in the hope of improving its water qualitytoxins, which can be harmful for humans and any other animals that come in contact with the contaminated water. There have been several cases of dogs being affected after playing in and drinking the lake waterturbidity, possibly a result of the bottom feeding of large numbers of introduced carp in the lakebarbecue facilities, fenced-in swimming areas, picnic tables and toilet facilities. Some of the parks reserved for public recreation include Commonwealth, Weston, Kings and Grevillea Parks, Lennox Gardens and Commonwealth Place. A bike path also surrounds the lake with riding, walking or jogging around the lake being a popular activity on the weekendsSailing and windsurfing are popular all year round. A rowing course is set up at the western end of the lake. Swimming is becoming less common due partly to concerns about water quality and generally cold water temperature.
Generally powerboat use on the lake is not permitted. Permits are available for the use of powered boats on the lake for use in rescue, training, commercial purposes or special interest (historic steam powered boats, etc)water skiing. Powerboats may be used in this limited areaFishing is quite popular in the lake with the most populous species being the common carp. The lake is stocked annually with a variety of introduced and native species, over 1.26 million fish have been released since 1964. Annual monitoring is carried out to determine fish populations. The 2001 survey only returned Carp, Redfin Perch and Golden Perch though there are other less common species also known to inhabit the lake, these include Silver Perch, Murray Cod, Rainbow trout, Brown trout and Goldfish.
Safety
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The lake is patrolled by the Australian Federal Police water police. The water police give assistance to lake users, helping to right boats and towing crippled craft to shore.
At most swimming locations around Lake Burley Griffin there are fenced-in swimming areas for safety. In the more popular areas, there are also safety lockers with life belts and emergency phones for requesting help. Between 1962 and 1991 seven people died from drowning in Lake Burley Griffinwater skiing.
Panoramic images
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Canberra-lake-panorama01_JAC.jpg Notable lakeside places
East Basin
Central Basin
West Basin
West Lake
See also
References
See also: Lake Burley Griffin, 1855, 1909, 1923, 1960, 1962, 1963, 1964