Enhanced reef: cast to sea

Earlier this month, you may have noticed the large barge stationed on the northern end of Te Whanganui-a-Tara.

Our iwi mana whenua partners Taranaki Whānui ki te Upoko o te Ika and Ngāti Toa Rangatira, project engineers and ecologists have completed an initial baseline evaluation which provides information to measure the growth of marine life and ecosystems in the area after the reef is built.

All reef units will be installed by mid-June this year and are part of a wider compensation package required under the consent conditions which include:

- Planting giant kelp to support this important plant species
- Research opportunities with Victoria University and iwi mana whenua
- Dune restoration along Pito-One (Petone) foreshore
- Installation of concrete tide pools within the project
- Inclusion of ecological textures to support marine growth on our concrete x-shaped blocks

These structures are being cast in locally in Seaview, Lower Hutt before they are loaded on to a barge to be carried to the reef site.
 
Image below: reef unit concrete yard in Seaview.

He kaitiaki ki te whenua, a guardian to the land

The resilient coastal edge protecting the road and rail is taking shape as the wall of armour extends between Wellington and Lower Hutt.

The specialised concrete blocks (known as XBlocPlus by their designers, a Dutch company called DMC)  are a unique cost-effective solution for Te Ara Tupua. These blocks are poured in the shape of an ‘X’, which interlock and stack on top of each other to create a seawall with a steeper incline. This design reduces the seawall’s physical footprint and impact on the marine environment. Using these blocks means less volume of material, and lower cost compared to a rock revetment, and creates the opportunity for innovative environmental design.

Te Ara Tupua is also the first project where seismic performance has been considered and tested in the design of these units, ensuring the new seawall will be resilient, despite being built over a large active faultline.

As a part of the project’s environmental compensation conditions, our ecologists and engineers worked closely with iwi designer Len Hetet to integrate the cultural design with the ecological enhancement. These include surface patterns and textures to encourage growth of underwater plants.

Including these within the concrete blocks is good value for money – the ecological textures fulfil a consent condition requirement to provide habitat on seawalls around the harbour’s edge. Without the patterned blocks, this would have required additional work alongside the project in other parts of the harbour.

Len Hetet shares the the name and narrative to these blocks:

"Te Ripowai speaks of the rippling water. It connects to our whakatauki of guardianship
Te Ati Awa tupua rau
He auripo i te manga iti
He auripo i te manga nui
He kaitiaki ki te whenua
Te Ati Awa of many phenomena
A ripple in our small tributaries
A ripple in our great waterways
A guardian on land
We must keep the ripples occurring speaks of the water living to which the land reciprocates
We as guardians must keep the ripples occurring if we do not and the water becomes still then life will cease to exist."

Image below: block with Te Ripowai design installed along the edge of Te Whanganui-a-Tara.

Ali Houpapa Cultural Advisor at Te Ara Tupua Alliance.

Infrastructure through a cultural lens

We have a few key people working in our team that ensure everyone working on site understands the significance of the environment that the project is being built on, including the iwi-owned land at Honiana Te Puni Reserve.

Meet Ali Houpapa. Ali is a Cultural Advisor at Te Ara Tupua Alliance and fondly referred to as Aunty around the construction site.

Aunty Ali who is uri (descendant) of Taranaki Whānui, inspires and connects our construction, design, engineering and environmental teams to the whenua, while sharing the Māori history, culture and narrative of the construction area.

She promotes a strong sense of responsibility to Te Ara Tupua and the resilience work that being completed to protect not only the rail and road but the history of the land for future generations to learn about.

Environmental Update

We are sad to confirm that three kororā/Little Blue Penguins have been found dead on the Ngā Ūranga ki Pito-One section of project site in recent weeks. The death of these kororā, is deeply saddening to all involved in the Te Ara Tupua works. 

Despite being found on site, the causes of death for two of the birds; the first found on Friday 26 April and the second found on Friday 3 May, have been investigated independently and initial findings indicate that they are not linked to construction works. 

Each of these two birds were sent to Massey University in Palmerston North for examination. Veterinarian experts conducted necropsies and report that one bird died of disease and the other died due to a physical injury not associated with the construction of Te Ara Tupua.

The third kororā was fatally injured by construction machinery on Saturday 18 May, at the southern end of the project. We are now investigating to determine what happened leading up to this, and how such an incident can be prevented in future.

NZTA Waka Kotahi and our partners that make up Te Ara Tupua Alliance are collating and reviewing findings as investigation into the incident continues. While this process is a priority, we do not have a specific timeframe for when it will be complete. We have informed the Department of Conservation and Greater Wellington Regional Council. 

We are now heading into our second kororā breeding season and have begun implementing new kororā habitats in some areas of the project. We have enhanced an area of the man-made coastline at the northern end of the project, near Honiana Te Puni Reserve, to provide increased nesting opportunities for the birds and protection from construction and dogs. Along the length of the project, the new coastline in future will provide even more habitat for kororā.

Waka Kotahi and the Alliance project team are committed to doing everything we can to better protect the environment and improve processes. We continue to work with the Department of Conservation and Greater Wellington Regional Council.

More information

For more information on the Te Ara Tupua project, contact us at TeAraTupua@nzta.govt.nz

Visit our website www.nzta.govt.nz/TeAraTupua