22 June 2009
NEW TUNNELS UNDER MELBOURNE
The construction of new sewerage tunnels 15 metres under Melbourne’s inner suburbs is about to get underway to cater for the city’s growing population and to protect the health of our rivers.
The $220 million Melbourne Main Sewer Replacement project will involve the laying of 2.3 kilometres of sewer pipe from Docklands to Port Melbourne.
Managing Director of Melbourne Water, Rob Skinner, said the new sewer would meet the demands of Melbourne’s population growth for the next century, and create up to 400 jobs in the process.
“The original Melbourne Main Sewer was built in the 1890s and while it has served the CBD and inner suburbs well, it needs to be replaced due to its age and capacity to keep up with urban development,” Mr Skinner said.
“This massive engineering project will also deliver health and environmental benefits, cutting the risk of sewage leaks into Melbourne’s waterways including the Yarra River and reducing the need for running repairs.”
A 164-tonne and 100-metre long tunnel boring machine will bore through Coode Island silt, sand and other materials, and has been named “Lucy Loo” after a competition among students at the local Port Melbourne Primary School.
While you could be forgiven for thinking the tunnel boring machine has been named after the famous actress, Lucy Liu, it was in fact a grade six student, Lucy Goudie, who named it after herself and the slang term for a toilet.
“The naming competition with school students shows our commitment to working with the local community to improve understanding of how major infrastructure projects such as this, will benefit them,” Mr Skinner said.
The tunnel boring machine will be lowered down a 15-metre vertical access shaft at Fennell Reserve, Port Melbourne, where it will first tunnel south to Swallow Street. It will then be reinserted at Fennell Reserve to tunnel north towards the Yarra River.
A major component of the project will be the crossing of the Yarra River upstream of the Charles Grimes Bridge.
Starting at South Wharf (south bank) and finishing at Flinders Wharf (north bank), the Yarra River crossing will be completed using a staged wet cofferdam construction method. A cofferdam uses steel sheets to build an enclosed area in which to work.
Specialist divers will work underwater within the wet cofferdam. This specialised work will include the installation of pipe supports, steel pipe, sealing and protection works.
A third of the Yarra River will be closed to marine traffic for each of the three stages of work, with each stage expected to take about eight months to complete.
Strict environmental controls will be in place while the sewer is built to protect the health of the Yarra River. There will be staged river closures to help minimise impacts on river traffic and to ensure there’s no impact on safety for river users or barriers to fish movements.
The Melbourne Main Sewer Replacement is being constructed by John Holland on behalf of Melbourne Water and will be completed during 2012.
Media Contact: Gavin Rainsford +613 9235 1587 +61 (0)400 690 502