CCNZ Construction Awards Nominee 2025
How do you separate stormwater across an entire community while working through backyards, around existing services and alongside homeowners?
Kerry Drainage & Civil took a drill-first approach to Waterview Stormwater Separation Stage 1, installing 1km of new public stormwater network and separating stormwater for 66 properties – while reducing reinstatement, construction disruption and waste.
Kerry Drainage & Civil was engaged by Auckland Council and Healthy Waters to deliver the first stage of the Waterview Stormwater Separation programme. The project involved installing approximately 1km of new public stormwater network, with pipe sizes ranging from 100mm to 525mm, alongside the investigation, design, consenting and construction of private stormwater separation for 66 properties.
As the first of eight proposed construction packages planned for the Waterview area, the project was strategically important. Kerry Drainage & Civil wanted to demonstrate that it could deliver a large-scale separation project to a high standard while providing value to the client and building strong relationships with the local community.
A key part of the approach was to drill first wherever practical, rather than defaulting to open-cut construction. KD Civil used directional drilling and pit drilling to install public mains and private laterals, often working within the tight confines of residential backyards. This reduced excavation and reinstatement, limited interaction with existing services and helped minimise disruption to residents.
The approach delivered significant results. Of the 21 public mains across the project, 13 were drilled rather than constructed by open cut. 42 of the 52 public laterals were installed by pit drilling, while three manholes were eliminated through alternative trenchless designs. Only 42% of the reinstatement allowance in the Schedule of Prices was ultimately claimed, representing a saving of approximately $200,000 for the client.
The trenchless-first approach also delivered substantial environmental benefits. By reducing excavation, spoil removal, aggregate deliveries and reinstatement, KDCivil reduced the project’s construction impacts and diverted more than 2,000 tonnes of spoil from landfill. Low-carbon concrete pipe was used where appropriate, while low-carbon manholes were also introduced in collaboration with Hynds at no additional cost to the client.
Private property separation presented a different challenge. KDCivil worked closely with homeowners to investigate existing drainage, develop individual solutions, obtain approvals and complete the physical works. Thorough investigation upfront helped the team identify opportunities to minimise reinstatement, including above-ground drainage solutions and trenchless installation beneath properties.
Stakeholder management was critical throughout the project. Before construction began, KDCivil helped organise a community BBQ and drop-in event to explain stormwater separation and what residents could expect during the works. The team also supported local businesses and helped establish a vegetable garden and learning programme at Waterview Primary School.
The project required close collaboration with GHD, who provided the design and engineering services, as well as Auckland Council and other stakeholders. Complex works on Great North Road also required careful traffic management and an engineered solution when KDCivil discovered that the existing stormwater connection point was actually a repurposed steel watermain. The team worked with the designer and Auckland Transport to develop and approve a specialist connection detail, completing the works within the agreed traffic management window.
The project was delivered with a strong focus on safety, quality, stakeholder relationships and value. Healthy Waters Project Manager Bruce Palmer described the client satisfaction as high, highlighting KDCivil’s prompt communication, collaborative approach and ability to accommodate additional requests. GHD similarly recognised the team’s collaborative problem-solving and ability to provide alternative solutions that reduced costs while maintaining strong health and safety performance.
The results extended beyond the original contract. KDCivil was successful in securing Stage 2 of the Waterview Separation programme, while approximately $800,000 of additional work was negotiated through a contract variation — around 18% of the original contract value. For KDCivil, it was a strong demonstration that a carefully planned trenchless approach could deliver better outcomes for the client, community and environment.
