Whitemans Road bulk watermain renewal



Wellington Water


Wellington Water


December 2022


Mobile Plant Fleet,Underground Services,Traffic Management,Pipe ramming, Rail crossings, Deep trenches

Customer Type:

Government & Local Government



Offline renewal of 150m of 200 dia. Bulk Watermain with new CLS pipe.

• A road crossing of Fergusson Drive a major strategic arterial route into and out of Upper Hutt.

• Work through a busy Metlink operated park and ride at Silverstream Station.

• A rail crossing of the Wairarapa lines just outside Silverstream Station.

• Installation over two existing stormwater culverts associated with and adjacent to The Silverstream – a tributary of the Hutt River.

• A crossing of the Whitemans Road, Gard St and Kiln St roundabout in Silverstream town centre.

• Work though the grounds of Silverstream Primary School.

• A deep crossing under an existing Stormwater culvert in the footpath and carriageway of Whitemans Rd.

• Work outside the Silverstream Shopping precinct.

Removing the existing pipe from a bridge structure over the Silverstream – including work at height and under the conditions of a resource consent.

This project was a tricky bulk water asset renewal project, rich with risks and challenges such as working within a rail corridor, major arterial routes and working through the grounds of a school - and outside a shopping centre - to name a few.

We’re proud of how we overcame these challenges to make the project a success. With excellent and experienced leadership at all phases of the project, translating good planning - and some dynamic problem-solving - into good delivery.


A key to success for this project was working with multiple stakeholders to secure access and construct the pipeline, including Upper Hutt City Council RCA, Metlink Park & Ride, Kiwirail & Silverstream School. Prior to the project we collaborated with Wellington Water to engage with each of these stakeholders so that the work could be efficiently completed. The team on site built positive relationships with all of the stakeholders, ensuring that our works did not compromise their needs.


We also worked closely with Wellington Water to overcome some design challenges. 


We used pipe ramming to install casings under busy rail and road corridors to minimise the requirement for excavation in and disruption of these transport routes.

With deep excavations in tight constraints between the rail corridor and a stream, we sunk a chamber onto the pipe ram to reduce the footprint of the site required. This meant we could dig to depth without encroaching on the rail corridor or carrying out significant enabling works in the stream.


During the project it became apparent that the thrust block design would mean that the blocks were complex, overlapping and unbuildable. We worked with Wellington Water to redesign the alignment to reduce the number of vertical and horizontal bends. This was achieved by installing the pipe in straight lines between specific crossing points and diverting other services to clear the route. 


This project won a 2023 CCNZ Award.