Te Ara Tupua, delivered by the NZ Transport Agency in partnership with iwi mana whenua Taranaki Whānui ki te Upoko o te Ika and Ngāti Toa Rangatira, creates a new resilient coastal edge to protect adjacent State Highway and rail infrastructure, while also providing a safe and attractive walking and cycling link between Wellington and Lower Hutt.  

 The Ngā Ūranga ki Pito-One (Ngauranga to Petone) section is the largest component, requiring coastal reclamation to build a 4.5km five-metre-wide shared path on the harbour coastline. Downer is part of the Alliance team formed to design and construct the Ngā Ūranga ki Pito-One section, as well as the Tupua Horo Nuku Eastern Bays Shared Path. 

Coastal works include 2.7km of sloping embankments (revetments) designed with the ability to adapt to rising sea levels, to protect and futureproof the shared path, and nearby road and rail line from the damaging effects of storms and waves. Six vertical seawall segments protect the shared path and avoid building revetments over high-value habitat areas. Offshore habitats constructed of naturalised rock forms are designed to support coastal bird life. 

Delivering improvements to the marine habitat and water quality to restore the diverse marine life has been a key feature of project delivery. A first for New Zealand, the works include design and construction of a five-hectare reef being built offshore from the Petone beach, to boost fish numbers and provide a home to sealife including octopus, crabs, crayfish and starfish.  

All site staff are trained in how to reduce risk for site ‘residents’ – oyster catchers, penguins, fish, kōura. Before working near rock habitats penguin dogs are used. Alongside the seawall construction, we have developed XBlocPlus precast blocks (formed primary armour), which were placed below the water where the patterned surfaces provide opportunities for marine life to grow.