Whispering Wall

The Barossa Reservoir's 'Whispering Wall' dams the Yattie Creek Gorge near Williamstown in the Barossa Valley to the north of Adelaide. The water supply comes through a tunnel from the South Para River. The dam is known as the Whispering Wall for the way in which it carries sound from one side of the Wall to the other. As the Wall is one part of a perfect circle, the sound waves bounce in a series of straight lines to the other side. The dam was designed by the Irish-born engineer Alexander Moncrieff and attracted worldwide attention at the time of its construction, as the idea of a tall but thin concrete structure curved against the pressure of the water was quite radical. The dam is more than 10 metres thick at the base and tapers to a narrow walkway at the top. It is constructed of primarily from concrete and 'plums' - quartz boulders blasted from the sides of the gorge. Old tram tracks were added for extra strength near the top. Construction of the dam began in 1899 and was completed in 1903. About 400 workers and their families set up camp near the building site at the height of construction.