Waterfall Corner, on the Brynderwyn Hills.
Photo: Supplied / Waka Kotahi

More than 300 repairs have been carried out to prepare detours around the Brynderwyn Hills ahead of the closure of a storm-damaged stretch of State Highway 1 next month.

The work, which has been carried out by Kaipara and Whangārei district council roading crews, includes resealing, improved bridge approaches, better signage, drainage upgrades, slip and subsidence fixes, vegetation clearance, and shoulder widening.

Northland Transportation Alliance maintenance and operations manager Bernard Petersen said the repairs would help get the scenic route, via Mangawhai and Waipū, and the freight route, via Paparoa and Oakleigh, ready for a sharp increase in traffic when the Brynderwyns closed on 26 February.

Petersen said NZTA Waka Kotahi planned to reopen the highway on 27 March for the Easter break, and close it again on 3 April.

In total, the highway was expected to be closed for about nine weeks.

Petersen said he was grateful to the roading crews for their “massive effort” to get the alternative routes in as good a condition as possible ahead of the Brynderwyn closure.

“The collaboration between 22 Kaipara and Whangārei-based contractors to get the job done has been superb, because they recognise how critically important this is for the region to get our routes into Northland in good shape.”

From left, Buster Sandford (Downer), Mike Monigatti (Hiway Stabilisers) and Sasha Linton (Downer) at work on a section of the Paparoa-Oakleigh detour.
Photo: Supplied / Northland Transportation Alliance

Petersen said many of the firms involved were Northland-owned, small- to medium-sized businesses subcontracted to the big three road maintenance contractors Ventia, Fulton Hogan and Downer.

About 14 percent of the detour length had been re-surfaced and 20 percent had been strengthened.

The combined 11.5km of upgrades had cost more than $5.5 million, funded by councils and central government.

Petersen said detour signage was being thoroughly updated to make sure motorists could easily understand and navigate the two alternative routes in and out of Northland.

Last time the Brynderwyns closed, following the Anniversary Weekend storm and Cyclone Gabrielle, some drivers complained about getting lost due to inadequate signage.

Much of the work carried out in recent weeks could not be completed last winter due to ongoing bad weather, so contractors had made the most of the recent dry spell.

Work would continue for the next few weeks, so Petersen was grateful to motorists for their ongoing patience.

He also urged drivers to take their time while using the alternative routes.

Those with time to spare could enjoy some of the attractions along the way, such as the Kauri Museum at Matakohe, which was just a seven-minute drive from the Paparoa-Oakleigh detour.

Meanwhile, truck-and-trailer units would be barred from the Mangawhai-Waipū detour, unless they were making deliveries along the route.

That was because of a hairpin bend on Waipū Cove Road where a number of large trucks got stuck when the Brynderwyns closed last year, causing major traffic disruptions.

Most freight vehicles would be able to use the Paparoa-Oakleigh route, adding about 20 minutes to the journey north.

Oversized trucks would have to take a longer detour via State Highways 12 and 14, increasing travel times by about an hour.

Originally NZTA Waka Kotahi had planned to close State Highway 1 over the Brynderwyns from 7 February, immediately after Waitangi Day.

That was shifted to late February following an outcry by Northland tourism operators, led by the Kerikeri District Business Association.