A warning alert has gone out to Coromandel Peninsula residents, asking them to prepare of the next bout of weather, and to move away from unstable land.

Thames Coromandel Civil Defence controller Garry Towler says people throughout the region should prepare for the next bout of bad weather.

The regional council issued a red warning ahead of forecast heavy rain which could add more woes to the already damage-stricken and sodden area.

Due to the red level weather warnings, the National Emergency Management Agency have issued advice on how to keep safe, scroll down to find the full list below.

"The regional council have serious concern that the land stability - that the land around the Coromandel [Peninsula] could be compromised due to sheer saturation," says Towler.

"That means that [anyone who] lives on a hilly section needs to keep an eye out - are there any cracks and that sort of thing? Because there is evidence that's starting to occur."

Waka Kotahi warns people not to travel in the area unless absolutely necessary, due to the state of the roads.

More heavy rain was expected from midnight Tuesday, January 31, until 6pm Wednesday, February 1, says the Thames Coromandel District Council.

Those in Matatoki and Matarangi are being urged to conserve water because there has been a heavy sediment load in the water supply because of the storm.

While people in Tairua, Pāuanui, Whangamatā and Onemana are also asked to use water carefully to ensure the supply continues.

Coromandel Peninsula businesses brace

Businesses in the area face uncertainty as more wet weather is set to hit the area ahead of Waitangi Day.

It comes after the region was cut off from road access in and out during Auckland Anniversary weekend - a normally busy time for coastal holiday towns - due to damage on roads and highways from days of significant rainfall volumes.

Tairua Campground manager Charlie Czepanski says there has been "100 per cent cancellations just about", during the long weekend.

Anchor Lodge manager, in Coromandel town, Sue Gill-Devereux says whether Waitangi weekend will be more profitable remained to be seen.

The town relies on the summer period for income, so the wet summer season will have a huge impact on businesses, she says.

Flooding in Matarangi, in the north of the Coromandel Peninsula, in the weekend Photo: RNZ/ Veronica Schmidt.

By Monday afternoon, some roads in the region had been reopened, and the region was no longer cut off, but UMU cafe's Josie Fraser remained cautious.

"Unfortunately our roads up here, they tend to continue slipping even if it's not raining.

"So the water builds up, and because it's a clay over rock, the clay will suddenly subside - and generally it continues to slip for at least three days after rain."

Meanwhile, the area's two main arteries to drive across the peninsula, State Highway 25A between Kopu and Hikuai, and State Highway 25 between Coromandel town and Whitianga, were closed due to slips and further cracks at a large washout.

With only three roads across the peninsula - and only one left open - being cut off again was a real concern for residents.

Many local roads were also affected, with details being updated on the district council's website here.

Czepanski said if all three highways were closed the only options left were air and sea access.

But Fraser says those options are limited too and the only option left is access by helicopter, which is weather dependent.

"We used to have ferry service [between Coromandel and Auckland], unfortunately Fullers pulled that this summer.

"That would have been an alternate route for people to get out," and people were really missing the service, says Fraser.

Because of the red level weather warnings issued for Auckland and the Coromandel Peninsula, the National Emergency Management Agency has posted advice on how to keep safe:

• Red weather warnings are the most severe warnings. The forecast weather could cause further flooding, slips and damage
• People should stay up to date with the forecasts from MetService and continue to follow the advice of civil defence and emergency services
• If you have evacuated, please stay where you are until you are given the all-clear to go home.
• Stay away from floodwater. Always assume that all flood water is potentially contaminated and ensure hands, clothes and property are thoroughly cleaned after contact with flood waters
• It is important to clean and dry your house and everything in it. Do not eat garden produce if the soil has been flooded
• Throw away all food and drinking water that has come in contact with floodwater, including things stored in containers
• Information about where to get help can be found on the Civil Defence website and from Auckland Emergency Management