Areas of rural Northland are still struggling with flooding, power outages and slips - days after Cyclone Gabrielle hit the area.

The storm tore through Hokianga on Sunday and Monday before causing catastrophic damage in Auckland, Coromandel, Gisborne and Hawke's Bay.

The severe weather warning is no longer in effect and Northland is in cleanup and recovery mode.

Geoff Crawford of Crawford Farms near Whangārei, says the cyclone wreaked havoc in the Hukurangi Swamp.

"We farm about 500 hectares of land on the Hikurangi Swamps, 450 hectares of it is under water at the moment.

"The Hikurangi Swamps is around 5200 hectares, probably 4500 hectares is under water" said Crawford.

Up to 90 percent of kūmara crops have been destroyed, he said.

"It's quite significant, it's going to be a major blow to the New Zealand economy.

"There's not going to be any kūmara from us this year."

A Northland farmer, facing a fifth day without power or water, said there had been absolutely no contact from civil defence or any other authorities since the cyclone struck.

Kaipara District, Northland on Tuesday. Photo: RNZ / Soumya Bhamidipati

Michelle Hill lives in Pikiwahine, south west of Whangārei, and told RNZ there were major slips and had been no power, very sporadic internet access and no running water since midday Monday.

Local farmers have cleared the road, but Hill said there had been no outside contact.

"Not at all...there was a helicopter that flew around a lot yesterday afternoon, a really big one - we can only assume it was Northpower or the army but the only real contact has been through the radio," she said.

Farmers were generally a "fairly hardy bunch" and had dealt with long power cuts before, she said, but what had been so striking this time was having no access to phones or the internet.

"When that fails, we could have gone back to smoke signals and pigeons and be better off, we really have no contact with the outside world and we've no idea when the power's coming on still - I've just been cleaning out my freezer because it's rotten.

"We've heard all these messages on the radio about websites to go to...but we've got no ability to get online, really kept in the dark - literally.

Hill said she recognised there were people elsewhere in great need but offered this advice: "If there are people out there who are linked to farmers, I'd say check on them, if they're family or friends, if you can, offer your support."

Northland Federated Farmers chief executive John Blackwell said he had been disconnected from civilisation.

"I think a lot of people are still stunned, it's hard to believe that we've had so many weather events in New Zealand this year - and we're only in the second month," Blackwell said.

Much of the kūmara supply comes from the Kaipara district, but this year there would be a shortage.

Towns in and near the Bay of Islands area in Northland, including Moerewa, Kawakawa, and Paihia, have seen damage, debris, flooding, and tree falls from Cyclone Gabrielle. Photo: Supplied / Joe Rapana

Kaipara mayor Craig Jepson said the worst was over for his region but hundreds were still in need of support.

Hundreds of households in Dargaville and the surrounding area were still without power.

Jepson's focus was on meeting the needs of people who are still struggling.

"I am really proud of the way the community and partner agencies have pulled together. It has been so good to be able to closely coordinate our efforts with FENZ, police and defence force services."

Northpower has done a great job of restoring power to almost 30,000 customers so far, he said.

Schools were also struggling with attendance rates because of damage to the roads and infrastructure.

Kaikohe East School Principal Chicky Rudkin said many students and teachers could not attend.

"Lots of our children have not come back to school just because they live in areas where there's lots of flooding so either their whānau don't have power or the busses couldn't get through.

"We had probably around 40 percent of our school role here yesterday and we've got staff that had no power for four or five days."

While the big clean up was underway, there was some light at the end of the tunnel for biggest outdoor event north of Auckland, the Northland Field Days was still scheduled to take place in Dargaville next month.