Sawyers Bay - Three Waters Pipe Renewals Project


Customer: Dunedin City Council

Contract: Construct

Location: Sawyers Bay, Dunedin




Project Capabilities

Civil Pipelines

 Fast Facts

  • Sawyers Bay Area C:
  • 2600m of new watermain, stormwater & wastewater pipelines
  • Dia ranging from 150mm – 375mm uPVC
  • Depth ranging from 0.75m – 2.6m


  • Sawyers Bay Area F:
  • 3800m of new watermain, stormwater and wastewater pipelines

The Sawyers Bay Three Waters Pipe Renewals Project is part of Dunedin City Council’s programme to upgrade ageing pipelines, some of which are now over 80 years old. Sawyers Bay is a small harbourside community between Dunedin and Port Chalmers in the South Island of New Zealand.

In October 2021, McConnell Dowell successfully tendered to join the Dunedin City Council’s three-contractor panel to provide onsite solutions in the upgrading and refurbishment of critical wastewater, stormwater and freshwater assets across the city of Dunedin, New Zealand. The project has six work areas to be completed in stages A, B, C, D, E, and F. McConnell Dowell was awarded the contract to complete Area C in July 2021. In May 2022, we were further awarded Area F. 

Our company is invested and committed to the mobilisation and setup of our team in Dunedin, and is mandated by McConnell Dowell’s New Zealand and Australian executive teams in line with the expansion of operations within New Zealand’s Water, Stormwater and Wastewater sectors.

The scope includes replacing the water, wastewater and stormwater pipelines and connecting these  new services to the existing networks before testing and commissioning them.

The majority of the asset renewals are in the public road reserve and will be carried out using open cut trenching methods. The team will reduce construction impacts by excavating in 6m sections, limiting the length of open trench at any one time.

However, the team will also be using trenchless technologies to minimise disruption to property owners where possible. Where the pipeline is on private property and structures have been built over the alignment of the pipe, re-lining of the exisiting pipe will be utilised to minise disruption to the residents.

Early engagement with our stakeholders is an important part of the job for the McConnell Dowell team and the overall success of the project. Where the pipeline crosses private property, our crews will engage with property owners to provide advance notification of our works and advise of temporary traffic and/or access changes.

To de-risk supply disruption during construction, all new water mains will be installed along new alignments.  Once the new pipelines have been tested and commissioned the old assets will be filled with grout (where appropriate) and/or decommissioned.

Once completed, the new pipelines will increase capacity within the network to allow for future growth, help reduce overflows and protect water quality in the area.

Area C was completed in May 2022 and works are now underway on Area F.

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