Brynderwyns Road Improvements

Fulton Hogan, in collaboration with NZTA Waka Kotahi, led the State Highway 1 Brynderwyn Hills recovery works to improve the roads and address environmental concerns.

This extensive project involved a 2km rebuild of the Brynderwyns in Northland. The remediation was carried out over a four month road closure and successfully addressed 18 slips caused by Cyclone Gabrielle.

The client

Fulton Hogan

The project

The SH1 Brynderwyn Hills recovery work

The challenge

Large areas of exposed soil posed a significant risk of contaminated run-off water entering nearby streams. Prime had to find a solution to prevent sediment from entering the waterway – which could contaminate the water and impact aquatic life.

Excavators and earthmoving equipment working below the exposed slip face at the Brynderwyn Hills.

The solution

EnviroHub lamella clarifier settling tanks were set up to capture run-off water. These systems automatically activate and dose according to pre-determined bench test parameters.

Prime's EnviroHub HL50 lamella clarifier positioned beside SH1 during the Brynderwyn Hills job

The outcome

Sediment was effectively prevented from entering the nearby waterways.


A level lamella clarifier by the roadside treating run-off water in the Brynderwyn Hills