31 August 2023

Hello everyone | Tēnā koutou katoa

We hope you're staying warm this August | Ākuhata as we count down the days until Spring | Koanga. Read on for more about:

• August | Ākuhata construction updates
• upcoming Whangaparāoa community events
• Wēiti River Bridge staging
• old house removal
• protecting freshwater fish
• sustainable construction solutions
• plastic free July

Aerial view of Whangaparāoa construction area with the old house, prior to its removal. Click the photo above to see more progress photos.

August | Ākuhata Construction Updates

If you’re travelling in the area, you may see new project signage being installed this month. Concrete bases for the local roads, Whangaparāoa Road and East Coast Road, went in last week. Once the concrete is cured they will put the actual signs up.

Here’s what we’ve been up to this month:

East Coast Road

• Constructed new access point to allow construction vehicles to safely exit our site on East Coast Road
• Progress on clearing vegetation on Ara Wēiti Road

Stillwater

• Building temporary access road
• Ground works to prepare for installation of temporary platform for the Wēiti Bridge construction (read more in this newsletter)

Whangaparāoa

• Fencing work continues
• Removal of old house (read more in this newsletter)
• Night works are underway to confirm the location of existing underground services. A hydro-excavation truck will remove the soil to expose the services.

Here’s what’s coming up soon:

Whangaparāoa

• Drilling a bore to ensure we have a water supply for construction purposes
• Continuing to construct access tracks
• Construction of erosion and sediment devices
• Begin ecological works before tree clearing
• Begin tree clearing

Stillwater

• Delivery of machinery and material to build the temporary staging
• Construction of temporary platform which will include auguring (drilling) and driving piles into the ground
• Construction of a temporary site office
• Preparation for the upcoming earthworks season 
• Construction of access tracks and erosion and sediment devices

SH1 and East Coast Road

• Preparation and installation of barriers on both sides of the motorway
• Construction of a level crossing for vehicles to safely travel between sites on either side of East Coast Road

Join us at a September Community Drop-In Session

Come along to one of our community drop-in sessions next month to meet the team and learn more about the project.

• Tuesday, 5 September 2023, 4:00 pm - 7:00 pm, Manly Bowling Club (56 Laurence Street, Manly, Whangaparāoa 0943)
• Saturday, 30 September 2023, 10:00 am - 1:00 pm, Hibiscus Coast RSA (43A Vipond Road, Stanmore Bay, Whangaparāoa 0932)

Wēiti Bridge western temporary platform works graphic.

Wēiti Bridge's Western Temporary Platform

Ground works are underway to prepare for the installation of a temporary platform on the Stillwater (western) side of the Wēiti River. Soon machinery and material will be delivered to site to build the temporary platform. Construction of the temporary platform will include driving piles into the ground, and will continue through to at least the end of the year.

To build the Wēiti Bridge, we need to build temporary platforms for us to work from. First, we needed to move about 20,000 cubic metres of earth to build out the temporary access track to the platform, working platforms, and laydown areas. The team have almost completed the earthworks required. To form the foundation of the platform, we will use 65 piles, each with a diameter of about 760 mm. The piles will extend up to about 20 metres into the riverbed. The western platform will be approximately 160 metres in length and span into the Wēiti River. Boat passage will remain open through this work.

Once the platform is ready, we will use a 280-tonne crane to carry out works on the western side of the river. Eventually, we will need to build a similar platform on the eastern side of the Wēiti River to continue our works.

View a larger version of the graphic above here.

Top photo: team working on site to remove old house. Bottom photo: old house before removal.

Farewell to Whangaparāoa's Old House

The old house in the former cedar Reserve, well-known to Whangaparāoa locals, was removed this month.

The team carefully removed the old house and sent off materials that could be recycled elsewhere through the removal company, Nikau. Nikau will sort it back at their site and once sorted they will send us details of what was diverted from landfill and recycled.

The project team was able to keep some carport timber, roof sheets, and the water tank to be used elsewhere on the project. Unfortunately the rest of the timber in the house was unsalvageable.

The removal of the old house is a step forward to main works starting this October. The Whangaparāoa construction site will stay busy through to the end of the project.

Check out more photos below of the site once the house was removed.

Top photo is a shortfin eel found on site and the bottom photo is a bully (common bully or Cran’s bully, hard to distinguish in the field).

Protecting Freshwater Fish

Our Ecology team is working hard to minimise project impacts on aquatic habitats and freshwater fauna. Efforts include:

• fish presence and absence monitoring
• fish salvage and relocation
• fish passage efficiency

These efforts are fundamental to managing potential impact on freshwater fauna.

Many New Zealand fish are diadromous. Diadromous means they need to migrate between freshwater and saltwater to complete their life cycle. When culverts and stream diversions are installed, this may result in fish losing access to existing habitats.

We use ecological surveys to identify whether fish exist upstream of existing culverts. If they do exist, we want to know what species are present. We will then use the data to design culverts. We'll ensure efficient fish passage through temporary crossings and designing appropriate permanent culverts. At the end of the project, we will check the efficiency of the culverts to make sure our designs work well.

To get baseline ecological data, we use different methods to detect what fish species are present. The first method uses environmental DNA (eDNA) sampling. This method captures DNA released by aquatic species to identify what's present. To do this, we collected water samples from our streams of interest, passed them through a filter, and then send them off for analysis. The lab results showed that fish were absent upstream of some culverts. Shortfin eels and banded kokopu are present in some of the very small streams.

The second method we use is trapping and electrofishing. Trapping involves setting minnow traps and fyke nets in the stream. We leave these overnight to capture fish. The electrofishing method involves passing an electrical current through the water. The current temporarily immobilizes the fish and makes them easier to catch. The fish are then collected, measured, and released back into the water unharmed.
We've completed fish monitoring upstream and downstream of four sites on the alignment. Using the above methods, we found:

• banded kōkopu
• shortfin eel
• gambusia
• common and Cran’s bullies

Next, we will use our survey results to design solutions for fish passage and fish habitats at stream diversions and culverts. We will also compare baseline fish data from pre-construction to post-construction survey data. This checks if the final design is effective in minimising impacts on native fish.

ESRC team on site with the O Mahurangi Environment and Sustainability team.

Exploring Sustainable Solutions for Construction Waste

The Unitec Institute of Technology Environmental Solutions Research Centre (ESRC) team recently visited our construction site for a tour. We met with them to talk about our environment and sustainability challenges and how we could address them. The ESRC team shared potential ways to tackle these challenges using sustainable and innovative solutions.

In one year, 25,000 tonnes of construction and demolition plastic go into Auckland landfills. Construction plastic is a large and complex challenge. For example, orange safety mesh is a staple on our construction site and used across the project. It is hard to recycle at the end of its life. With the help of ESRC, we are looking into a more sustainable alternative.

The construction industry contributes to almost 50% of all landfill-bound waste. An approach ESRC recommends to reduce construction waste is focusing on prevention and reduction. It’s something that can be put in place quickly and is relatively low cost. An example of this approach is encouraging careful waste sorting by using clear signs with images. Working with ESRC will support us in achieving our Sustainability Policy outcomes. 

We value the importance of using expertise to help progress modern and sophisticated solutions so that healthier and more sustainable transport options are available to us all. We hope to set a precedent for future infrastructure projects and reshape the approach to construction waste.

Read more on the sustainability work underway on O Mahurangi - Penlink: nzta.govt.nz/projects/penlink/sustainability

Plastic Free July ideas included shopping at op shops for stocking our staff kitchen.

Plastic Free July Recap

Plastic Free July is a global movement that helps millions of people be part of the solution to plastic pollution so we can have cleaner streets, oceans, and beautiful communities. It is a challenge (not a competition) intended to make you think about all the single use plastic we use every day.

"Although the size of the plastic waste problem is frightening, the
numbers tell us that small steps can make a big difference." - Rebecca Prince Ruiz

As mentioned in the article above, Unitec’s Environmental Solution's Research Centre (ESRC) has found that the plastic waste from the construction industry needs to change. In just Auckland alone, the ESRC estimates that construction and demolition produces 25,000 tonnes of plastic waste annually.

Some of the O Mahurangi sustainability targets that are combatting waste include:

• 90% by volume of inert and non-hazardous waste (construction waste) is diverted from landfill
• 60% by volume of office waste is diverted from landfill
• 100% by volume of spoil (excavation material) is diverted from landfill

Check out more of our targets set out in the Sustainability Policy.

To promote and create a sustainability culture shift, we ran a Plastic Free July challenge with our project teams last month. We asked them to submit a sustainability win, idea, or concern they have. The submissions could involve the design / planning space, the operational construction space, or their home. Many submissions were received but a few stood out against the rest: 

• Re-purposing old curtain rail holders as hooks for drying gear
• Turning old tyres found on site into flower beds
• Setting up a compost bin
• Shopping at op shops for staff kitchen set up
• Learning how to splice rope left us with less waste, as the team tied leftover rope to make new lengths

The choices we make now in our everyday lives towards reducing our waste can carry a big impact and help make the world a more thriving, better connected and safer place both for ourselves and for our future generations.

Whakapā Mai | Contact Us

For more information on the O Mahurangi - Penlink project, contact us on 0800 PENLINK (0800 7365 465) or at omahurangi@nzta.govt.nz.

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