SH1/SH29 Cambridge to Piarere Intersection Upgrade

WSP joined forces with Waka Kotahi, Mana Whenua, and the local Waikato community to develop transportation infrastructure that seamlessly integrates road safety, environmental conservation, and cultural significance. Together, their efforts ensure that roads connect not just places but also people, all while honouring the essence of the Waikato region.

SH1/29 - A war forward for prioritising safety and environmental conservation

Not so long ago, the SH1/29 intersection was notorious as one of New Zealand's most dangerous intersections. As part of the New Zealand Upgrade Programme (NZUP), a transformation is underway, prioritising not only safer roads but also the preservation of our precious environment.

Waka Kotahi, Mana Whenua, and the Waikato community have united to safeguard the surrounding wetland and lake ecosystem.

In 2020, WSP was commissioned to design a stormwater treatment system that supports and enhances nature for the new intersection. This resulted in a two-lane roundabout with a central island spanning 60 meters. It's raised about 3.5 meters to accommodate walkways and cycling lanes, a bridge between safety and sustainability. This is more than a road upgrade; it's a journey towards a safer, greener future.

SDG ALIGNMENT

Location

Hamilton, New Zealand
Waikato, New Zealand

Client

Waka Kotahi

Project Value

$50m CAPEX

Project Status

Construction complete in 2025

How we approached Waka Kotahi's challenges

WSP tackled intricate stormwater challenges with the design of robust infrastructure that not only counteracts the impacts of natural hazards but also embraces cultural values, adapts to evolving Resource Management Act (RMA) regulations, and proactively addresses climate change concerns.

Collaboration and strong partnerships were the key to success

Throughout this project, WSP and Waka Kotahi have prioritised building a robust partnership with Mana Whenua to shape the design of the wetlands and stormwater infrastructure. WSP led the consultation with Mana Whenua, focusing on stormwater and hydrological aspects, to gain insights into Māori key focus areas and the cultural significance of the environmental context in terms of stormwater and hydrology.

The solution included Mana Whenua water narratives being woven into the design to adapt the behaviour of the stormwater flow and disposal methods.

WSP fostered a ‘one-team’ collaborative culture by integrating Waka Kotahi into the project team from the very start. The focus on transparent communication encouraged the team to share issues and solutions as often as possible, which also allowed experts and clients to leverage each other’s experiences to solve problems faster.

Our team engaged with stakeholders from multiple disciplines: landscape designers, archaeologists, water specialists, and ecologists. This collaboration resulted in the stormwater design sitting alongside ecology, archaeology, and landscaping reports and concepts in the resource consent application.

SUSTAINABILITY

What if we could design our infrastructure to work with nature, instead of against it?

Sustainable, resilient infrastructure design means implementing greener, low-impact stormwater solutions.

For example, we limited the number of rigid concrete pipes, manholes, catch pits, and headwalls to be used only where absolutely necessary. Designing with the future in mind, enabled us to not only mitigate the effect of natural hazards but go beyond the traditional approach to similar projects with a focus on resilience, compliance and cultural considerations key to its success.

“The hope is that the story and the history of the area is woven into the solution. When the project is finished and we walk away, it is not only an upgraded intersection but also safer for our community and will give credence to some of the history of the region.”

Josiah Simmonds Stormwater Design Lead, WSP

Josiah Simmonds Stormwater Design Lead, WSP

COMMUNITY

What if we could connect and communicate with our community in a more meaningful way?

Te Mana o te Wai concerns the restoration and preservation of the balance between wai (water), te taiao (the environment), and the community.

By adopting this concept into our programme of work, we were able to communicate and connect with the community in a more meaningful way.

In return, we were able to work closely and successfully to design a project that is significant for all stakeholders – from Waka Kotahi, through to Mana Whenua and the local communities.

RAUTAKI MAORI

What if Te Ao Māori was embedded into our way of doing things?

Cultural impact reports were undertaken prior to the project starting, informing the design through a cultural lens. Collaboration with iwi resulted in improved project delivery and added immense value, with the Mana Whenua endorsement expediting the subsequent consenting process.

Mana Whenua affirmed that the proposed restoration measures and management of stormwater achieved the objectives of Te Ture Whaimana.

These objectives include erosion and sediment control good practices; capture and conveyance via constructed planted wetlands; wetland swales for water quality prior to discharge to the Waikato River and Waitoa Stream; and overflow structures for high-flow events.

FUTURE READY

What if we planned for the future today?

The increasing effects of climate change were also accounted for in the infrastructure of the stormwater system, which is designed to last for the next 100 years.

Predicted higher storm intensities combined with longer period of droughts resulted in the decision to design a larger stormwater pipeline infrastructure and we adapted the design of the wetlands to ensure planting could withstand a range of extreme weather.

WSP took a multi-disciplinary approach, working closely with stakeholders including ecologists and landscape designers, to ensure a successful stormwater design.