The replacement of the old water main will reduce the risk of disruption to the water supply as well as other issues associated with water main bursts.

So far, $A10 million has been spent on the project. The project has been divided into four stages, with all but stage three completed.

Stage one was completed in August 2005 in which ACME Construction carried out work from Stanhope Street to Toorak Road. Approximately 2.1 km of 375 mm DICL & MSCL water mains were laid including the installation of pipe across Toorak Road, High Street and Glenferrie Road. Due to the proximity of tram tracks, the installation was carried out by microtunnelling.

Stage two commenced following the completion of construction at Station Street in July 2005. It involved work stretching from Glenferrie Road to both sides of Stanhope and Dandenong Roads and along Station Street. Construction was carried out by DKM Utilities and 2.1 km of 300 mm DICL and MSCL pipeline were laid out.

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Trenchless Technology was carried out between Glenferrie and Colboro Roads with a laser bore. A 31 mm by 500 mm bore was made under the tram tracks. The use of laser technology allowed the bore to be kept straighter for longer and also to be laid on grade if necessary.

However, as a large machine shaft measuring 5 m by 3m was required for the boring machine, three days were spent on completing the job as time had to be allocated towards setting up, boring and laying the conduit.

Between Glenferrie and Wattletree Roads, a directional drill provided by Ace Energy Services had to drill an 8 m by 500 mm bore under the tram tracks. As a machine shaft was not required, setup and removal times were sped up. As a result the job was finished quickly with four hours spent on completing the 8 m bore.

Despite shorter time spent, a longer distance of 15 m was necessary to get down to the required depth of 1.2 m. Stage two was completed in early 2006 after a hiatus during the Christmas trading period to minimise disruption to the public.

In January 2006, stage three construction commenced from Stanhope to Warra Streets. DKM Utilities carried out construction again, laying 4 km of 150 mm DICL and MSCL pipelines. It involved a 2.1 km excavation and 1.9 km lift and relay.

Construction is still ongoing with two bores running across Glenferrie Road at Russell Street and at Warra Street to be completed.

Stage four work running from Glenferrie to Callantina to Barkers Road has been completed with four kilometres of 225 mm DICL and MSCL pipelines being laid.

During this stage, several difficulties were encountered. There was a tendency for the bore hole to collapse, especially in refill ground or near other services. Also, when boring across a major road, there was difficulty in finding space for the shaft due to the location of other services. However boring in line with the water main was not as complicated.

Due to their rigid joints and long pipe lengths, installing a straight bore for welded mild steel pipes proved tricky as any rocks present could cause a minor deflection. Sometimes property connections could also be missed in commercial areas.

Yet Trenchless Technology proved advantageous not only towards reinstatement costs, but also because it enabled construction to be carried out without interrupting traffic or creating an eyesore. Cost was also kept down as closing down lanes and operating traffic management works would have been more expensive.

Preliminary planning and investigation of the area was integral at this stage. The shaft also had to be prepared in advance and covered with a plate until the subcontractor was ready.