State Highway 25A Taparahi Slip Remediation

Customer:  Waka Kotahi NZ Transport Agency 

Contract: Design & Construct

LocationCoromandel, North Island, New Zealand

Transport Solutions New Zealand & Pacific Islands

Fast Facts

  • National recovery project
  • 124m long, 15m high bridge
  • Tight 9 months delivery timeframe
  • 3-span composite design
  • Pre-cast concrete deck
  • Over 100 people working on and off site
  • In a remote location with difficult access
  • Tight delivery timeframe


McConnell Dowell with joint venture partner Fulton Hogan and designers Beca and Tonkin + Taylor was awarded the State Highway 25A Taparahi Slip Remediation by Waka Kotahi NZ Transport Agency. 

This project is to rebuild a section of State Highway 25A after the road collapsed following the major storm event earlier in the year. This is the only direct route through the Coromandel ranges, and the closure is significantly impacting people’s ability to travel. 

Despite a tight programme and completion date due for March 2024, the team has been working tirelessly to reconnect the Kōpū and Hikuai communities as quickly as possible. The bridge and the road will be reopened before Christmas, three months ahead of schedule. 


The challenge 

The team has had multiple challenges to manage during the construction of the bridge. It is a high-profile project with interest from a broad range of stakeholders - including residents, businesses, truckers, tourists, and bach owners, - all eagerly awaiting the reopening of the road. Some of the delivery issues identified were: 

  • Extremely tight timeframe for delivery
  • Variable geotechnical conditions, 
  • Wet weather conditions - July is the wettest month of this period with an average of 94mm of rainfall 
  • Site access, a track to the site needed to be cleared before work could start
  • The remote location doesn’t have services such as water or power 


The solution 

Our accelerated approach to delivering the design and construction of SH25A has been the key to delivering the bridge and restoring access within a short timeframe. 

Our team constructed a three-span composite bridge with pre-cast concrete bridge deck sections, a concrete sub-structure, and a steel superstructure. We selected this design as it utilises readily available materials, is simple and quick to build, and has a proven track record throughout Waka Kotahi’s network. 


The Key to Success 

Our team has a proven track record of delivering time-critical projects including America’s Cup Project (AC36), Auckland’s Downtown Infrastructure Development Programme (DIDP), and upgrading SH6 and SH20B. 

A work culture that prioritises collaboration, and builds a “one-team” mentality, generates ideas that boost productivity, helped us to fast-track the delivery of SH25A. Building a united, high-performing team requires a thoughtful approach. We fostered a collective sense of ownership, and empowered team members to be creative, so people challenge the status quo. By holding daily check-ins where ideas and issues can be discussed we facilitated open communication and inspired teamwork. Forming a relaxed social environment for off-shift staff provided a comfortable space for camaraderie, and connection and helped improve well-being.  

Project Gallery


Daniel Patten
Daniel Patten
Engineering Manager