Famous whispering wall effect created by engineering marvel of South Australia's Barossa Reservoir dam
The curved wall of Barossa Valley Reservoir dam at South Australia's Williamstown, north of Adelaide, was part of its unique early 20th Century engineering features but it also created a famous whispering wall effect that became a tourist attraction.
Image courtesy ABC (Australian Broadcasting Corporation) News, Adelaide
South Australia’s Barossa Reservoir dam at Williamstown gained world attention for its structure, built between 1899 and 1903, but it became a wonder for another reason.
Designed by the state’s engineer in chief A.B. Moncrieff, the dam was Australia’s largest and among the world’s first true arch concrete dams with other unique features.
Constructed using local materials, including dolomite and limestone, the dam featured a curve that follows the valley contours. The contours made the wall famous as the whispering wall – with acoustic characteristics that surprised the working constructing it. Words whispered at one end of the dam wall could be heard clearly at the other end of the dam 144 metres away.
The whispers could be heard due to the parabola effect. The wall formed one part of a perfect circle, causing soundwaves that hit it to bounce to the other end. Acoustic experts have studied the wall to better understand the principles of sound transmission and the effects of temperature and humidity on sound waves.
Barossa Reservoir Reserve became a popular tourist destination just an hour’s drive north from Adelaide city centre. The reservoir, with its whispering wall open to the public from 9am to 5pm, was close to Williamstown and Gawler, just south of the Barossa Valley. The wetlands around the reservoir were in a protected conservation area for many native species, including koalas and kangaroos, and birds. The surrounding area also had walking trails and picnic spots. A visitor station provides information about the history of the wall, the local flora and fauna, and the engineering behind its design.
