Arlington Apartments — 3 Waters



Hawkins Infrastructure Ltd./Wellington City Council




June 2017 – June 2018


Mobile Plant Fleet, Underground Services, Traffic Management, Connections 

Customer Type:



Construction of approximately 600m of new Stormwater drainage, 330m of new Wastewater Drainage and 400m of new Potable Water for a new Development. Including connections and disconnections from the public network.

This project included some significant challenges associated with working on a busy construction site in a brownfield suburban environment. Funding constraints and design issues meant that we had to work closely with the main contractor and developer to come up with value for money solutions to issues that arose before and during construction. The whole project team collaborated well and met problems head. The result that the product was of a high quality and the delivery process was an enjoyable one for all parties – focused on outcomes throughout.

During the procurement phase we engaged in an informal ECI process to value engineer some aspects of the design and bring the project closer to the developer’s budget. Through that process we developed lasting relationships – based on trust with the main contractor and developer.

Inside the boundary we had to work closely with the main contractor so that we could undertake the trenching work and allow them to continue construction of the buildings and their facades. The phasing was challenging and the interfaces with multiple trades needed careful supervision on site. We proposed some trenchless solutions to sections of the work where the programme was so tight that the structures were being completed ahead of the civils work. In one particular case a drain was installed under a new structure by horizontal directional drilling rather than delay the programme to work bottom up.

Testing proved that the material on site was contaminated and there was a risk of a significant cost increase because of this. We worked with the main contractor and developer to mitigate the additional cost by balancing productivity on site while minimising cut to waste. Our team were careful about disposal of the material in order to ensure that the environment was protected and consent conditions were met.

Outside the boundary we worked in Taranaki St, Hankey St and Hopper St to complete connections and disconnections from the public network. We directly delivered a traffic management solution for the work and liaised with Wellington City Council RCA to ensure the plan met their constraints.

We worked with the WWL Operations Engineer to plan and execute a successful water shutdown that allowed us to cut into the main and make water connections and disconnections. This included liaising with surrounding businesses, planning to meet their specific constraints and then communicating details of the service interruption to them. The connection was a 100mm ID PE from a 150mm ID CI main. A water meter and backflow preventer were installed as part of the domestic connection.

The drainage connection work was completed under a public drainage permit and directly delivered by our team. This included sliplining a section of existing main and some open trenched connection sin the road corridor.

Throughout the construction we managed inspections with the Wellington City Council building inspection team and the WWL land development team to ensure that the product was completed to the required standard and handover of the asset at the end of the project was completed smoothly. The water main was pressure tested pressure rebound test), chlorinated and bug tested before connection to the main.

As built information for the private network was supplied to the developer for their use in closing building consents. As Built information for the connections – including a water meter as built – was provided to WWL and the developer so that it can be included on the GIS network.

This project included some significant challenges, both commercially and at the workface. Through it we delivered a quality product and formed relationships with other organisations that we continue to value. This type of work is at the core of our business and this project demonstrates some of our key capabilities. We can deliver value for money by self-delivering all aspects of the construction, providing efficiency by delivering all three waters in the same mobilisation and traffic management set up. We have strong project management capabilities that match our technical expertise, we can manage change well and can ensure that our customers have confidence throughout the delivery process that the product will be of a high quality and will be handed over seamlessly.