O Mahurangi – Penlink

1 August 2024

Celebrating two years of the O Mahurangi Alliance

This month we recognised the two year anniversary of the signing of the O Mahurangi - Penlink Project Alliance Agreement. There has been a lot of progress since work began in 2022, and especially during the summer months and the bulk earthworks season we’ve just had. We’d like to thank the community for their collaboration and commitment to this project as it steadily progresses.

Click on the image above to open it in a new tab and zoom in as needed.

Please note the following definitions when reading the infographic:

• Wick drains are vertical drainage systems that serve as an escape route for water during soil compression. Wick drains reduce the time it takes for water to escape, speeding up water removal from silt and decreasing settlement time.

• Counterfort drains are drains that address areas where there is evidence of subsurface water. These drains are 500mm wide and vary from 3 to 6m deep and work by intersecting broken zones in the soil structure, offering a way for trapped water to escape.

• Sediment retention devices include both sediment retention ponds and decanting earth bunds. When it rains, they catch the dirty water running off site for treatment. They hold the dirty water and let it settle, so the dirt stays trapped on site and the clean water is released back into the environment. This video shows how we test a sediment retention pond on site.

During the winter season our focus shifts from bulk earthworks to working on structures and some detailed earthworks. The next bulk earthworks season is due to start in October.

Click on the image above to watch the video on YouTube.

Behind the scenes

Watch a behind the scenes video of construction progress on site as well as hear from our Alliance Project Manager and Environmental Supervisor.

Check out our latest flyover video of the project using footage from April to May 2024 prior to winter works close out.

You can also check out aerial photos on the project website: www.nzta.govt.nz/projects/penlink/gallery

Temporary Wēiti River channel closure

At the start of July, we temporarily closed the Wēiti River channel to enable the construction of a temporary staging platform on the eastern side of the river. This platform will provide access for equipment and staff to allow for the construction of Pier 4, including the much safer transfer of a large 280 tonne crane to the eastern side.

The closure will be in place until the end of August. The channel closure does not affect vessels navigating the river downstream of the worksite. Once reopened, an approximate 18-metre wide navigable gap will be available for vessels to pass through.

There will be times, for short periods of the day during work hours, where loads will be lifted over the gap and vessels will be unable to pass. Our normal hours of work are Monday to Friday 7am to 6pm and Saturday 8am to 4pm.

Should there be any changes to the above dates, due to unforeseen circumstances or the works are completed earlier than expected, a notification will be sent with full details.

A second closure is planned for later in the year.

We apologise for any inconvenience caused and thank all river users and neighbours for their patience during the ongoing construction of the new Wēiti River Bridge. Should you have any questions in regard to these works, please don’t hesitate to contact us.

Please note: This map is indicative only and is not to be used for navigational purposes.

Temporary diversion road to Stillwater

A temporary diversion road for Duck Creek Road opened in July to allow for construction of the new Duck Creek Road connection to continue.

The two way diversion will remain in place until further notice – at times, we may need to use further temporary traffic management in the form of lights or a stop go.

An email notification will be sent prior and if you live nearby and would like to be notified, sign up for work notifications here.

Check out the general arrangement plans here to see what the future Duck Creek Road connection will look like.

Auckland Transport Duck Creek Road slip repairs

If you’re heading to Stillwater, you will have noticed more traffic management on the road and work underway. This Auckland Transport (AT) work is to repair the area on Duck Creek Road that was damaged during the Auckland Anniversary weather event in January 2023.

This essential work, which includes constructing retaining walls on both sides of the road, installing additional drainage, new kerb and channel, completing road pavement repairs and landscaping, began at the start of July and is expected to take 8 months to complete.

While the section of Duck Creek Road where the AT team are working will remain open, it is reduced to one lane of traffic through the work site. They will use a mix of temporary traffic management, including a reduced speed limit and temporary traffic lights.

Both AT and the O Mahurangi team thank you for your continued patience.

More information

For more information on the O Mahurangi – Penlink project, email us at omahurangi@nzta.govt.nz or call us on 0800 7365 465.

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