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.
What you need to know
Where | Mill Flat Road Bridge, near 6 Mill Flat Road |
When | Early-mid September 2025, for up to one week (Dates to be confirmed, this website will be updated) |
Hours of work | Full Road Closure - Nightworks only (9pm-4am)
- Installation of construction steel beams and concrete panels beams (will be kept to a minimum)
Shoulder closure - Day works - 7 am – 10 am (shoulder closure only)
|
What we’ll be doing | - Delivery and construction of crane and crane pad (a stable area for the crane to operate)
- Delivery, lift and installation of the 32-metre-long steel bridge beams, and precast panels established
- New traffic management road layout for motorist and staff safety, with signs and VMS board to guide drivers through detours
- Testing everything to make sure it works well
|
Duration | Up to 6 weeks total (weather dependent) - in several stages highlighted below |
Why | - Bridge construction: As a vital connection for over 200 residents on Mill Flat Bridge, over 1,500 vehicles use this intersection during peak hours—and that number’s set to rise by up to 26% in the next 5 years
- Safety issues: It’s tough to turn safely, especially during busy times. Fast-moving traffic makes it risky for drivers, buses, and heavy vehicles.
- Future growth: New housing will bring even more cars, making current problems worse if we don’t act now.
|
How travel is affected: | Temporary Intersection Layout - Up to 1 Week
A crane will be positioned on the road at the northwestern corner of the Mill Flat Road / Coatesville-Riverhead Highway intersection. This will temporarily change how the intersection operates:- Coatesville – Riverhead Highway and Mill Flat Road Bridge - The current single-lane traffic light setup 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.
Full Road Closure - Nightworks only (Map below)- To safely lift and place steel bridge girders, a full closure of the intersection will be required for one night. This closure will last for approx. 3 hours, with work taking place overnight to minimise disruption.
- Resident Access: For residents on Mill Flat Road and near the works area on Coatesville-Riverhead Highway, escorted access may be facilitated during the closure, but only when it is deemed safe by the site team – delays should be expected.
- Detours in Place: Detours will redirect traffic via Ridge Road and Wake Road, or Glenmore Road and Ridge Road.
- Emergency Access: We are coordinating with emergency services and will have contingency plans in place for any emergencies.
Short Intermittent Closures - Throughout the week - To safely lift and place bridge panels, there will be brief closures (around 5 minutes each) at the intersection during the day, across 2–3 days.
- These short closures will occur throughout the week, both day and night. Road users may experience brief delays at the traffic lights while each lift is completed safely.
The exact dates for this work will also be shared in the next update. |
How to get around: | See detour maps on this webpage |
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.
- Full Road Closure - Nightworks only (Nightshift work would be kept to minimum)
- To safely lift and place steel bridge girders, a full closure of the intersection will be required for one night. This closure will last for approx. 3 hours, with work taking place overnight to minimise disruption.
- Resident Access: For residents on Mill Flat Road and near the works area on Coatesville-Riverhead Highway, escorted access may be facilitated during the closure, but only when it is deemed safe by the site team – delays should be expected.
- Detours in Place: Detours will redirect traffic via Ridge Road and Wake Road, or Glenmore Road and Ridge Road.
- Emergency Access: We will be coordinating with emergency services and will have contingency plans in place for any emergencies. The exact date and time of this closure will be confirmed in the next update.
- Detour route applies on this stage, attached to the images and documents on this page.
- 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.
Detour while Mill Flat Bridge is closed overnight
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
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.
What you need to know
Where | Mill Flat Road Bridge, near 6 Mill Flat Road |
When | Early-mid September 2025, for up to one week (Dates to be confirmed, this website will be updated) |
Hours of work | Full Road Closure - Nightworks only (9pm-4am)
- Installation of construction steel beams and concrete panels beams (will be kept to a minimum)
Shoulder closure - Day works - 7 am – 10 am (shoulder closure only)
|
What we’ll be doing | - Delivery and construction of crane and crane pad (a stable area for the crane to operate)
- Delivery, lift and installation of the 32-metre-long steel bridge beams, and precast panels established
- New traffic management road layout for motorist and staff safety, with signs and VMS board to guide drivers through detours
- Testing everything to make sure it works well
|
Duration | Up to 6 weeks total (weather dependent) - in several stages highlighted below |
Why | - Bridge construction: As a vital connection for over 200 residents on Mill Flat Bridge, over 1,500 vehicles use this intersection during peak hours—and that number’s set to rise by up to 26% in the next 5 years
- Safety issues: It’s tough to turn safely, especially during busy times. Fast-moving traffic makes it risky for drivers, buses, and heavy vehicles.
- Future growth: New housing will bring even more cars, making current problems worse if we don’t act now.
|
How travel is affected: | Temporary Intersection Layout - Up to 1 Week
A crane will be positioned on the road at the northwestern corner of the Mill Flat Road / Coatesville-Riverhead Highway intersection. This will temporarily change how the intersection operates:- Coatesville – Riverhead Highway and Mill Flat Road Bridge - The current single-lane traffic light setup 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.
Full Road Closure - Nightworks only (Map below)- To safely lift and place steel bridge girders, a full closure of the intersection will be required for one night. This closure will last for approx. 3 hours, with work taking place overnight to minimise disruption.
- Resident Access: For residents on Mill Flat Road and near the works area on Coatesville-Riverhead Highway, escorted access may be facilitated during the closure, but only when it is deemed safe by the site team – delays should be expected.
- Detours in Place: Detours will redirect traffic via Ridge Road and Wake Road, or Glenmore Road and Ridge Road.
- Emergency Access: We are coordinating with emergency services and will have contingency plans in place for any emergencies.
Short Intermittent Closures - Throughout the week - To safely lift and place bridge panels, there will be brief closures (around 5 minutes each) at the intersection during the day, across 2–3 days.
- These short closures will occur throughout the week, both day and night. Road users may experience brief delays at the traffic lights while each lift is completed safely.
The exact dates for this work will also be shared in the next update. |
How to get around: | See detour maps on this webpage |
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.
- Full Road Closure - Nightworks only (Nightshift work would be kept to minimum)
- To safely lift and place steel bridge girders, a full closure of the intersection will be required for one night. This closure will last for approx. 3 hours, with work taking place overnight to minimise disruption.
- Resident Access: For residents on Mill Flat Road and near the works area on Coatesville-Riverhead Highway, escorted access may be facilitated during the closure, but only when it is deemed safe by the site team – delays should be expected.
- Detours in Place: Detours will redirect traffic via Ridge Road and Wake Road, or Glenmore Road and Ridge Road.
- Emergency Access: We will be coordinating with emergency services and will have contingency plans in place for any emergencies. The exact date and time of this closure will be confirmed in the next update.
- Detour route applies on this stage, attached to the images and documents on this page.
- 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.
Detour while Mill Flat Bridge is closed overnight
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
