We’re building a new bridge on Mill Flat Road, Coatesville

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Update - 19 May 2026

We are now approaching the final stages of the Mill Flat Road Bridge and the associated road improvements along Coatesville Riverhead Highway and Mill Flat Road. We are on track to complete the project as planned in mid-2026.

In Mid-June 2026, asphalt resurfacing of the intersection will require the full closure of the bridge.

We anticipate this bridge closure to be the last one required before completing the project. Further details available on our letter here.

Update - Oct 2025

Stage 1 of Mill Flat Bridge is officially open.

Update - 15 Oct 2025

Girder installation was successful, with the bridge beams and precast panels to be installed shortly afterwards.


About the Project

On the afternoon of Friday 27 January 2023 (Auckland Anniversary Weekend) the bridge was washed away during a significant flood event. In addition to the bridge structure being washed away, the following damage also included the Eastern abutment wingwall was washed away, and experienced a scour with exposed abutment beam piles, and the Western abutment experienced some damage.

Post-event, temporary access was established through a forestry track, and a temporary Bailey Bridge was constructed within six days in the same location and opened to the public on the afternoon of Monday February 6, 2023.

Auckland Transport undertook a long-term rebuild of the bridge destroyed in the January 2023 floods, with a new two-lane bridge designed to withstand future extreme weather events. Construction began in April 2025 and is progressing steadily, with traffic maintained via a single lane and completion expected within 12–16 months.

With our contractor JFC, we will need to establish road closures and traffic management layout changes while equipment and bridge structures are delivered to the construction site. A crane will be positioned on the northwestern corner of the Mill Flat Road and Coatesville-Riverhead Highway intersection.

The work we’ll be doing and traffic management & detours

  • Coatesville – Riverhead Highway and Mill Flat Road Bridge
    • The current single-lane traffic light on Coatesville-Riverhead Highway and Mill Flat Road Bridge will continue outside of working hours. During working hours, Traffic Controllers will be in place to assist safe operations through the intersection.
  • Exiting Mill Flat Road:
    • Vehicles can only turn right (southbound) onto Coatesville-Riverhead Highway. Left turns will not be available.
  • Entering Mill Flat Road:
    • Northbound vehicles on Coatesville-Riverhead Highway can still turn left into Mill Flat Road. Right turns into Mill Flat Road will not be available.
  • We’ll try to start the work on time but factors outside our control, such as weather could mean a delayed timeline. If the delay is significant, we’ll notify you and update this webpage regularly.
  • Take care while driving, walking, or cycling in the area. Follow all traffic signs, signals, and directions for safety.
  • We will personally liaise with effected residents to minimise any disruption. Traffic controllers will be on site to assist during these closures.
  • Construction will run between Day and Night shifts to finish as quickly as possible. We know our work can be a bit loud, and that noise – particularly at night – can be disruptive. We’ll try to keep noise levels down.


Benefits to the Community

  • Improved Traffic Flow: The new bridge will help manage the increased traffic volume, reducing delays and congestion.
  • Enhanced Safety: The project will address safety concerns by making it easier for drivers, buses, and heavy vehicles to find safe gaps in traffic, reducing the risk of accidents.
  • Future-Proofing: By accommodating the expected growth in vehicle numbers due to nearby planned housing developments, the intersection will be better prepared for future demands.
  • Reliable Bus Services: The intersection improvements will ensure that bus services remain reliable and efficient, benefiting public transport users.
  • Community-Driven: The project reflects on the feedback and priorities of local residents, ensuring that the upgrades meet the community's needs.
  • Optimal Use of Funding: The plan makes the best use of the available Local Board Transport Capital Fund, ensuring that the investment delivers maximum benefits.


Where we’ll be working

Before the work starts, a work notice letter (attached in important documents on this webpage) will be delivered to affected residents to inform the community about the disruption, lane closures and detours on surrounding roads.

We appreciate your patience during this work. Please follow detour signs when installed at the site.


How to contact us

Our team will be on-site to keep things running smoothly. If you have any queries or concerns about this project, please contact AT:

Email: ATengagement@at.govt.nz (include reference Mill Flat Road Bridge)

Phone: 09 930 5090

If you have any queries related to the construction, please contact contractor JFC Ltd

Contract Manager: Richard Docherty

Project Manager: Bernardo Lamela

Email: MillFlatBridge@jfcltd.co.nz

Phone: 021 420 189 / 021 420 612

Update - 19 May 2026

We are now approaching the final stages of the Mill Flat Road Bridge and the associated road improvements along Coatesville Riverhead Highway and Mill Flat Road. We are on track to complete the project as planned in mid-2026.

In Mid-June 2026, asphalt resurfacing of the intersection will require the full closure of the bridge.

We anticipate this bridge closure to be the last one required before completing the project. Further details available on our letter here.

Update - Oct 2025

Stage 1 of Mill Flat Bridge is officially open.

Update - 15 Oct 2025

Girder installation was successful, with the bridge beams and precast panels to be installed shortly afterwards.


About the Project

On the afternoon of Friday 27 January 2023 (Auckland Anniversary Weekend) the bridge was washed away during a significant flood event. In addition to the bridge structure being washed away, the following damage also included the Eastern abutment wingwall was washed away, and experienced a scour with exposed abutment beam piles, and the Western abutment experienced some damage.

Post-event, temporary access was established through a forestry track, and a temporary Bailey Bridge was constructed within six days in the same location and opened to the public on the afternoon of Monday February 6, 2023.

Auckland Transport undertook a long-term rebuild of the bridge destroyed in the January 2023 floods, with a new two-lane bridge designed to withstand future extreme weather events. Construction began in April 2025 and is progressing steadily, with traffic maintained via a single lane and completion expected within 12–16 months.

With our contractor JFC, we will need to establish road closures and traffic management layout changes while equipment and bridge structures are delivered to the construction site. A crane will be positioned on the northwestern corner of the Mill Flat Road and Coatesville-Riverhead Highway intersection.

The work we’ll be doing and traffic management & detours

  • Coatesville – Riverhead Highway and Mill Flat Road Bridge
    • The current single-lane traffic light on Coatesville-Riverhead Highway and Mill Flat Road Bridge will continue outside of working hours. During working hours, Traffic Controllers will be in place to assist safe operations through the intersection.
  • Exiting Mill Flat Road:
    • Vehicles can only turn right (southbound) onto Coatesville-Riverhead Highway. Left turns will not be available.
  • Entering Mill Flat Road:
    • Northbound vehicles on Coatesville-Riverhead Highway can still turn left into Mill Flat Road. Right turns into Mill Flat Road will not be available.
  • We’ll try to start the work on time but factors outside our control, such as weather could mean a delayed timeline. If the delay is significant, we’ll notify you and update this webpage regularly.
  • Take care while driving, walking, or cycling in the area. Follow all traffic signs, signals, and directions for safety.
  • We will personally liaise with effected residents to minimise any disruption. Traffic controllers will be on site to assist during these closures.
  • Construction will run between Day and Night shifts to finish as quickly as possible. We know our work can be a bit loud, and that noise – particularly at night – can be disruptive. We’ll try to keep noise levels down.


Benefits to the Community

  • Improved Traffic Flow: The new bridge will help manage the increased traffic volume, reducing delays and congestion.
  • Enhanced Safety: The project will address safety concerns by making it easier for drivers, buses, and heavy vehicles to find safe gaps in traffic, reducing the risk of accidents.
  • Future-Proofing: By accommodating the expected growth in vehicle numbers due to nearby planned housing developments, the intersection will be better prepared for future demands.
  • Reliable Bus Services: The intersection improvements will ensure that bus services remain reliable and efficient, benefiting public transport users.
  • Community-Driven: The project reflects on the feedback and priorities of local residents, ensuring that the upgrades meet the community's needs.
  • Optimal Use of Funding: The plan makes the best use of the available Local Board Transport Capital Fund, ensuring that the investment delivers maximum benefits.


Where we’ll be working

Before the work starts, a work notice letter (attached in important documents on this webpage) will be delivered to affected residents to inform the community about the disruption, lane closures and detours on surrounding roads.

We appreciate your patience during this work. Please follow detour signs when installed at the site.


How to contact us

Our team will be on-site to keep things running smoothly. If you have any queries or concerns about this project, please contact AT:

Email: ATengagement@at.govt.nz (include reference Mill Flat Road Bridge)

Phone: 09 930 5090

If you have any queries related to the construction, please contact contractor JFC Ltd

Contract Manager: Richard Docherty

Project Manager: Bernardo Lamela

Email: MillFlatBridge@jfcltd.co.nz

Phone: 021 420 189 / 021 420 612

Page last updated: 20 May 2026, 09:16 AM