The National Local Government Engineering Medal for 2003 was recently awarded to Group Manager Public Works and Services, Tony Reed, and Ryde City Council for the West Ryde Drainage Tunnel Project.
Presented at the International Public Works Conference held in Hobart in August, this prestigious award recognises excellence in the design and/or construction of a Local Government engineering project.
The tunnel project was the result of options developed for the West Ryde shopping precinct following severe flooding between 1984 and 1990. The preferred option was to construct a tunnel 2.7 kilometres long and 3.6 metres in diameter to convey 50 cumecs away from the Ryde CBD into Parramatta River.
The project incorporated comprehensive engineering works, extensive community consultation and environmental considerations.
Several tunnelling methods were tested to progress safely through the soft ground. This caused major construction delays. Eventually, a heading and bench method was used in favour of full face excavation. Negotiations with Sydney Water over the protection of a major water main in the tunnel route also caused delays, and the tunnel completion date was extended from August 1999 to July 2000.
The project included the installation of CDS Technologies’ largest pollution control unit in Australia to improve water quality entering Parramatta River. Most stormwater flows from the tunnel into the unit, then into the cut and cover culvert section under Meadowbank Park.
The tunnel portal is located at the edge of Meadowbank Park soccer fields. As a result, Council has upgraded the playing fields as part of the tunnel project, installing below ground drainage and an automated irrigation system.The tunnel also includes several ancillary drainage lines at Denistone and West Ryde.
Council funded the $14.5 million project through a 4.5 per cent special rate increase, which received general community support and State Government approval.
The project clearly demonstrates the capacity of Local Government to resolve a major community problem through appropriate consultation, strong engineering management and a commitment to environmental sustainability.
Tony Reed said that the tunnel has also provided a cost effective solution to localised flooding.
“The existing drainage system was inadequate and largely under buildings,” he said. “Improvement by traditional cut and cover measures would have been costly and difficult because of the disturbance to buildings, roads and parks. The construction of the tunnel reduced the cost of work from $16 million to approximately $10 million.”
For further information contact Tony Reed, email treed@ryde.nsw.gov.au or telephone (02) 9952 8102.
