The Royal Parade water main renewal project upgraded one of Melbourne’s largest water assets in the heart of the city’s CBD.

The 133-year-old pipe was experiencing leaks and showed signs of deterioration. This meant there was an increased chance of a major burst, an event that would have had major consequences for the busy road and the education, transport and healthcare precincts it serviced.

Along the 2.1km pipe alignment, the team needed to work closely with stakeholders to ensure the success of the project. This included Yarra Trams, Fire and Rescue Victoria, City of Melbourne, Melbourne Uni, Royal Melbourne Hospital and Carlton FC.

The main was renewed trenchlessly by slip lining, which involved installing a new DN560 high density polyethylene pipe (HDPE) inside the existing DN750 wrought iron cement lined water main. A 100mm temporary water supply for Ikon Park (Carlton FC) was set up for the duration of the project to ensure the football club and its patrons had a continuous, reliable supply of water.

After slip lining, all existing connections were reconnected to the renewed pipework, including divide valves, offtakes, bypasses, fire service connections, scours valves and flow meters.

The challenge

Royal Parade is one of Melbourne’s busiest roads with tens of thousands of vehicles using it daily. At times, the entire 2km length of the southbound traffic lane was closed to facilitate works.

Crucial to the project’s success was reducing the impact of works on traffic and the local community, which included two hospitals and Carlton Football Club.

Slip lining was chosen because it is a low impact and fast to install. However the challenge for the Royal Parade delivery team remained: how could they further reduce the project duration and minimise their site footprint to the benefit of the communities?

The solution

To reduce their impact, the delivery team needed to find creative ways to make slip lining more efficient and reduce the project duration and footprint.

One efficiency measure introduced was to order pipe in 20m lengths rather than the standard 12m. This reduced the number of welds from 160 to 100 and resulted in a significant time reduction. A welding site 200m long was also established away from the road to facilitate the process and store welded lengths.

To minimise disruption to the community, the project team decided to renew a 1600m section in one shot. Interflow proposed using glide foil, typically used for GRP CIPP installations, to facilitate this.

Other measures included timing works around nearby Metro Tunnel construction to avoid delays, conducting a Traffic Impact Assessment before commencing, and obtaining at 10-hour working window to reduce project duration.

Conclusion

The Royal Parade water main renewal safeguarded one of Melbourne largest water assets for generations to come. Interflow and Fulton Hogan upgraded the 2.1km water main while delivering exceptional outcomes for the community.