Thursday, August 25, 2011
Scrivener Dam is what holds back the waters of the Molonglo River to form Lake Burley Griffin. It was closed to start the lake filling in 1963, but because of a drought it took nearly seven months to go from a trickle of water and a few mosquito-breeding ponds to a proper lake, but when the drought eventually broke, it only took a few days to fill.
The dam was named after Charles Robert Scrivener, the surveyor who recommended the site for Canberra in 1909. It wasn't his original choice - we could have been in the Snowy Mountains, and the ACT might have included Australia's highest peak, Mt Kosciusko. Apparently he didn't get on too well with Walter Burley Griffin, the winner of the design competition for Canberra, and Scrivener had the influence to change the design for three connected lakes, at different levels, into the single lake we have today.
The dam itself is 33 metres high and 319 metres long. It holds back 33 million cubic metres of water, in a lake with a 40.5km shoreline. It was built to withstand a 5000 year flood event, and the flood gates are tested every three months. If you're interested, there's more information on a fact sheet from the National Capital Authority.
In the background is part of the National Arboretum, and on the far side of the dam, to the left, is the National Zoo and Aquarium.