A new bridge maintains vital water infrastructure in the Wellington region, with the added benefit of a cycling and walking connection across the Hutt River trail.

Whakawhirinaki (the Silverstream Water Bridge and shared path) provides a seismically resilient bridge crossing for the replacement of the Te Mārua to Karori Pipeline, and walking and cycling connections to the popular Hutt River trail, increasing recreational connections across the river.

The Te Mārua to Karori pipeline runs from the Stuart McCaskill Lakes to Karori, supplying around 40% of the bulk water to Wellington and all of Porirua’s water. The current alignment runs parallel to State Highway 2, crosses the Hutt River at Silverstream Road Bridge and then runs north along Fergusson Drive. The existing pipeline is deteriorating, and Silverstream Road Bridge is predicted to experience significant damage in a major earthquake event, making the pipeline also vulnerable. 

Worked with


Project date

2018 - ongoing

In 2018, Boffa Miskell provided natural character, landscape, and ecology inputs into the Multi-Criteria Analysis (MCA) process to select a preferred site and method of crossing; and subsequently prepared the Landscape and Visual Effects Assessment and Ecological Effects Assessment as part of the Resource Consent Application for the bridge.

We prepared detailed design drawings for hard and soft landscape elements for the bridge surrounds, and an Urban Design and Landscape Plan (UDLP) for discharge conditions relating to the resource consent. Visual simulations of the proposed bridge accompanied the resource consent application and assisted with project communications.

The location within the Te Awa Kairangi/Hutt River corridor meant the appearance of the bridge, its integration with the surrounding landscape, and ability to create improved recreational connections were important outcomes. The urban design and landscape architecture treatments were undertaken with two key considerations – the bridge as an architectural feature within the river corridor, and the bridge as a user experience for pedestrians and cyclists.

As a distinctive form within the river corridor, visible from roads parallel to the river as well as recreation areas and walkways, the design augments the bridge's architectural qualities as a landmark, enhancing its presence rather than diminishing it. Lighting of the arch structure emphasises its form and profile, and reduces the chance of birds that use the river as a navigation device colliding with it. The colour is based on shadows among native bush along the riverbanks. This helps integrate the structure within its context, without attempting to make it recede visually.

At the early stages of the project, the western bank of the river was identified as a previous release site for lizards, which required a Lizard Management Plan to be established to provide guidance for the management of lizards in all areas within the construction footprint and for the duration of clearance works.

Established planting in the area by Forest and Bird was identified and measures developed to minimise any impacts. Consideration was given to appropriateness of species in relation to whole of life maintenance, compatibility with the local environment and contributing to amenity and ecology (such as lizard friendly planting) without compromising safety and personal security.

The Boffa Miskell team worked closely with mana whenua during the detailed design, and the outcomes have been incorporated into the final design of the bridge environment. We also worked closely with the engineering team to ensure the seismic and engineering requirements of the bridge provided a fit with the wider design outcomes.