NZ Transport Agency Waka Kotahi has confirmed State Highway 2 north of Matawai will remain closed for “several weeks” as a result of major damage caused by heavy rainfall on Friday.
The closure will delay roadworks on another part of the highway and comes as Gisborne freight drivers look to transport summer crops.
More than double (322mm) the area’s average rainfall for January fell in 48 hours.
It caused multiple instances of flooding and slips, trapping people travelling through in the Waioweka Gorge between Matawau and Ōpōtiki and leading to more than 40 people being evacuated by helicopter.
“It turned gullies into waterfalls, overwhelmed and blocked culverts and triggered widespread debris flows across the road,” a NZ Transport Agency Waka Kotahi (NZTA) spokesman said.
“The road is expected to remain closed for several weeks with up to 40 slips in total to repair.”
Crews worked hard throughout the weekend at both ends of the gorge to clear smaller slips and gain access to the larger areas of damage.
“Geotechnical investigations and drone surveys confirm the situation is far more complex than first anticipated.”
NZTA Waikato and Bay of Plenty manager for maintenance and operations Roger Brady said the scale of the damage meant people should be prepared for a longer closure.
“Our crews are doing everything they safely can, but the sheer number of slips and continuing amount of debris falling mean this is a complex and challenging situation. The safety of our crews will always come first,” he said in an NZTA statement.
Brady said there were two significant slip sites at either end of the gorge, which had been declared safe to begin work on.
Crews proceeded with caution to begin to remove slip material on Monday afternoon.
“The immediate focus is on removing debris where possible and clearing blocked culverts so the road surface and underlying structures can be properly assessed once river levels recede.”
The damage included four to eight “larger slips”.
“Given the scale of damage and uncertainty about the condition of the road underneath the debris, we expect the closure to extend well beyond a short-term response,” Brady said.
SH2 from Matawai to Gisborne remained open but NZTA urged motorists to continue to drive to the conditions over coming days.
“Be alert to the possibility of other slips and debris following heavy and persistent rainfall in the area last week.”
Police were alerted to the first slip in the Waioweka Gorge about 9am on Friday, but conditions rapidly deteriorated.
Further slips and flooding cut off motorists and by midnight on Friday helicopters had evacuated everyone known to be trapped.
Eastern Bay of Plenty area police commander Inspector Nicky Cooney said another eight people at two private properties were due to be flown out on Saturday morning.
“I want to acknowledge the efforts of local helicopter pilots, New Zealand Defence Force staff, local and regional councils, and Police Search and Rescue.”
A Royal New Zealand Air Force (RNZAF) NH90 helicopter flew 35 people out of the Gorge on Friday night. They were taken to welfare centres in Ōpōtiki and Matawai.
The crew managed to complete rescues just as the weather began to deteriorate again.
“We likely couldn’t have done much more and there very well could have been unprepared people left out overnight,” chopper skipper Flight Lieutenant George Bellamy said.
Cooney said it was a long operation and they were thankful everyone was safe.
“The recovery of the evacuees’ vehicles will take some time given the significant damage and number of slips through the gorge.”
Police were on the ground to co-ordinate the RNZAF helicopter’s rescue efforts.
NZTA has carried out aerial inspections.
Gisborne Mayor Rehette Stoltz said the damage was “extensive”.
“This has a huge impact on our local businesses, residents travelling to health appointments at Waikato Hospital and visitors or students having to travel north or come home. Economic as well as environmental impacts,” she wrote in a statement on social media.
On Monday, NZTA said as a result of the SH2 closure, planned overnight closures of SH2 south at Devil’s Elbow in Hawke’s Bay had been postponed.
“These closures were to begin on Sunday night while crews finished asphalting the area,” the NZTA spokesman said.
A Gisborne-based primary producer, who declined to be named, said the road closure would mean more work for them.
“We will carry on but it will make it more difficult to get our products to our customers out of Gisborne. It is a pain in the backside, but it’s something we’ll deal with. It will just add to our costs.”
A Gisborne-based freight company operator said the closure would have a huge impact “because of the summer crops just coming on in Gisborne, with apples under way on Friday last week and sweetcorn still going”.
“We have to go via Hawke’s Bay and that’s adding to our costs, with driver accommodation, extra gear and so on,” he said.
“We want SH2 north open as soon as possible, but for it to be done safely for road crews and for our trucks afterwards.”