Ecology of Te Hakao Minden Gully is pivotal as bridge construction begins


Construction has started on a collection of three bridges that will cross the Te Hakao Minden Gully at Te Puna, as part of a major interchange being built for the Takitimu North Link project.

Waka Kotahi Regional Manager of Infrastructure Delivery, Jo Wilton, says work in this area will also see the restoration of the ecologically and culturally significant Hakao stream and gully – one of the wider benefits provided by this New Zealand Upgrade Programme (NZUP) investment.

“This is an important location for the project as the build will be significant for the major interchange. The site is also very special as Te Hakao Minden Gully is an area of cultural and ecological significance. The stream is an important tributary that links the mouth of the awa, Wairoa River to Te Rangituanehu Minden.”

Te Hakao Minden Gully has steep faces that slope down to the gully floor and the Hakao stream below. There will be three bridges built to cross the gully, ranging between 140–150m long. A mainline bridge, an eastbound on‐ramp and the westbound off‐ramp bridge.

People standing in a shallow stream

Ecologists and kaitiaki undertaking the pre-construction baseline freshwater surveys in the Hakao/Minden Stream.

Jo Wilton says, “Our aim is to leave things better than before, and there is an enormous programme of ecological and environmental work that will take place as part of this project and NZUP projects across the country.

“During freshwater surveys Longfin Eel, Shortfin Eel, koura (freshwater crayfish) and kākahi (freshwater mussels) were identified in the Hakao stream –  highlighting just how precious this waterway is.

“As part of the project the gully will be restored in this area, planting a variety of native plants as well as restoring a significant length of stream banks. This will provide an enhanced environment for native fish and bird species to thrive.”

Close up view of mussel in a plastic container

Finding kākahi (freshwater mussels) highlights how precious this waterway at Te Hakao stream, Te Puna.

While construction is in progress, temporary bridges will be built to protect the stream and provide access for construction vehicles.

Bridges construction

Piling work is expected to take about seven months and involves a 280-tonne crane driving 129 piles approximately 20 metres into the ground. There is 2.5km of piling work – nearly 30% of the whole project.

The mainline bridge will carry two lanes of traffic in each direction. The new Takitimu North Link expressway will connect onto this bridge.

The on‐ramp bridge will carry a single lane of traffic with shoulders from Te Rangituanehu / Minden interchange to the west, across Te Hakao Minden Gully, to safely merge onto the new Takitimu North Link road.

The off‐ramp will carry a single lane of traffic with shoulders across Te Hakao Minden Gully to link into the Te Rangituanehu / Minden interchange to the west.

A three-metre-wide shared path for walking, biking and other modes of active transport will be separated from the traffic by a rigid barrier.

The Te Hakao Minden Gully bridges are expected to be completed late 2024. Timeframes are subject to change depending on ground conditions and weather.

Aerial view of construction site

Aerial photo over Minden Gully – August 2022.

About the project

As part of the Government’s New Zealand Upgrade Programme investment in better travel options, the Takitimu North Link project connects Tauranga and Te Puna with a new 6.8km expressway and shared path. It’s all about ensuring people get where they’re going safely.

Projects worth $2.1 billion, including the Takitimu North Link, are now under construction as part of the New Zealand Upgrade Programme.

To find out more about the project go to link)

Artist impression of the completed Te Rangituanehu / Minden Interchange.