Torrens Weir, Adelaide, SA
When the Colony of South Australia was proclaimed in 1836 the City of Adelaide was founded on the southern side of the River Torrens.
The River Torrens was, at that time, was a series of shallow summer water holes. The Torrens was occasionally a flood threat.
Sir Edwin Smith was the mayor of the City of Adelaide in for two periods, 1879-1882 and 1886-1888. He had a vision to ring the city up to modern standards and part of the plan was to conversion of the River Torrens into a lake to improve its appearance and create a recreational facility.
To create the lake a weir was constructed on the western part end of the City of Adelaide. The first weir was in 1867 when the Sheriff of Adelaide used prison labour to construct a timber dam. The dam washed away in 1872.
The current concrete weir was designed and constricted in 1881. The design and construction were supervised by the City Engineer and Surveyor of Adelaide, J.H.C. Langdon. The weir is a gravity dam, slightly curved upstream in plan. It was one of the first uses of concrete on a civil engineering project in Australia. The cement was imported from England and was mixed with aggregate from Aldgate in the Adelaide Hills. In this original form the weir had three pairs of 3-foot diameter sluices.
The sluices were closed for the first time on 1 July 1881 and formal opening ceremony was held on 21 July 1881.
The weir created a lake approximately 1 mile long and 100 to 200 yards wide.
With the weir relying on over topping to clear flooding and the weir impeded the flow. This resulted in deposits of silt and mud upstream of the weir reducing the already relatively shallow lake.
The build up of silt was partially reduced by dredging. In 1913 the City Engineer for Adelaide, J.R. Richardson, proposed that two Sluices should be installed at the weir to reduced silting. A preliminary design was prepared by funding was released for the works. In 1924 the then City Engineer, R.M. Scott took up the design of the sluices.
To design the sluices gates a study of the River Torrens was made to determine the maximum discharge of the river. Further, in 1926 a 1/200 scale model of the proposed sluice gates was made to test the sluice gates in all conditions.
IN May 1927 a contract was awarded to underpin the existing apron and wing walls to alleviate the effects of scour. This work was completed in January 1928 and works on the sluice gates started three months later. The sluice gate contact was completed in April 1929 and was officially opened on 23 May 1929.
References:
Scott, R.M. "Torrens Lake Sluice Gates". Journal of the Institution of Engineers, Australia incorporating Transactions of the Institution, Vol. 3, No. 8, August 1931.
