The Whakawhirinaki Silverstream Pipe Bridge is a new infrastructure project spanning the Hutt River in the Lower Hutt region of New Zealand. It replaces an ageing bulk water-pipeline crossing that was in poor condition and vulnerable to earthquakes and flooding. The bridge carries a one-metre diameter steel water main that supplies drinking water from the Te Mārua Water Treatment Plant to Upper Hutt, Stokes Valley, Porirua and parts of Wellington city: about 60 million litres per day.
In addition to its critical water supply role, the bridge also incorporates a shared path for pedestrians and cyclists, enhancing recreational connectivity across the river corridor. The design features a three-span steel structure: a 100 metre long, 20 metre tall central arch weighing about 150 tonnes, flanked by steel trusses on either bank. It has been engineered to withstand significant seismic movement, the existing pipeline crossed an active fault and the new design accommodates fault slip and flood resilience. Work commenced in early 2023, and the bridge and pipe became fully operational in October 2025.
