Potholes and chip seal

At times, heavy rain has resulted in several significant potholes quickly forming between Kaipara Flats Road to Sheep World.  When this has occurred we have reduced the speed through the project site to ensure everyone’s safety.  The project team have then temporarily repaired these potholes as soon as it is safe to do so.

The plan was to seal the area before the wet, winter weather hit but the first COVID19 lockdown delayed this work and took us into the wetter months.

As the weather becomes warmer and drier, the project team will begin laying chip seal.  Sealing will occur at night and is likely to start later this month.

New wooden retaining walls northbound

Retaining walls

The primary function of a retaining wall is to offset gravitational forces and prevent the retained earth from slipping down with erosion over time or in bad weather.

When building these retaining walls, the project team needed to resolve several issues including:

• In some places the ground water table was less than 10m below the surface and the team used a hydro-excavation truck to remove this water before putting piles in place. 
• Pile holes next to an existing culvert had to be lined because the sides of the drilled holes were unstable;
• The project team found rock and timber at some pile sites and a core barrel had to be used to core through these obstructions before the piles could be installed.

Some interesting facts:

• The project team have installed 365 wall piles and used 1200m2 of timber.
• Pile depths range from 2m to 12m and the longest pile is 16.6m.

An interesting story, but perhaps not one for the squeamish.  A rat ran into an 8m deep pile hole but managed to jump onto the submersible pump and then out of the hole before the project team finished pumping the ground water out and lifted the pump up.

New planting and landscaping

Stormwater treatment and layby enhancement

The large layby/picnic area northbound on State Highway 1, just before Waitaraire Bridge was closed for about six weeks to enable the team to construct a stormwater treatment area.  The project team have planted more than 2,500 locally sourced plants including cabbage trees (Ti Kouka), flax (Harakeke) and native grasses (Purei and Upohotanga). 

The plants will help slow down the movement of water and remove rubbish and contaminants from the stormwater runoff, improving the water quality before it enters the local waterway and eventually the Hotio River.  Stormwater treatment areas also provide refuge and attract a variety of wildlife.

Flexible road safety barriers

The project team will be installing just under one kilometre of flexible road safety barrier from Sheep World south toward Warkworth in mid-November.  The project team will install a further 2.2 kms between Hotio Bridge and Waitaraire Bridge in late January 2021.

Flexible road safety barriers are far more forgiving on the human body in both car and motorcyclist incidents than any other type of barrier.

They are designed to prevent traffic leaving the road or crossing the centre line and colliding with hazards such as other vehicles, trees and poles. They 'catch' and then redirect vehicles creating a more forgiving road that can help prevent mistakes becoming fatal.

Flexible road safety barriers work best on straight sections and gentle curves. Most importantly, when fitted along the centre or the side of the road, they significantly reduce deaths and serious injuries.

NX2 - connecting SH1 to Puhoi to Warkworth - nightworks

From Thursday 10 September, the Ara Tūhono - Pūhoi to Warkworth Project plan to carry out night works on SH1 between Hudson Road and the Kaipara Flats Road / Goatley Road intersection.

The project team will be undertaking ground investigation, utility trench works, service relocations, drainage works and vegetation removal during this time.  This work is weather dependent and poor weather may mean that on some occasions, planned work will roll over to the next fine night.

Stop/go traffic management will be in place from 7.00pm to 5.00am Sunday to Thursday nights only. The works outlined above are expected to be completed by Thursday 1 October, weather permitting.

Please note, additional night works are also planned from October to the end of December 2020.

The area in red below shows where on SH1 the Puhoi to Warkworth project team will be working in the coming weeks.

More information

For more information on the SH1 Dome Valley project, contact us at northlandproject@nzta.govt.nz

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