Blocked North Island roads have reopened after yesterday's torrential rain but authorities warn there could be more flooding in Waikato, where a stranded farmer had to be plucked to safety by helicopter this morning.
The rain eased today in Waikato, Coromandel and Bay of Plenty, but a severe weather warning remains in place for Gisborne, where more heavy rain through to this evening could cause flooding and slips.
Road crews today worked to clear highways that were closed by slips and flooding in Coromandel, Bay of Plenty and Waikato yesterday.
The New Zealand Transport Agency said State Highway 2 at Karangahake Gorge and SH25 between Thames and Coromandel had reopened, but motorists should continue to take care on highways in the area while clean-up work continued.
Yesterday's torrential rain caused flooding throughout parts of Waikato, where a flood-stranded farmer had to plucked to safety by helicopter this morning after he was forced to shelter in a barn overnight.
The 59-year-old man was feeding stock on his farm south of Te Aroha last night when he was caught out by the rising Waihou River, which flooded the back paddocks bordering the river.
Waikato police search and rescue coordinator Constable Dave Pitchford said the man's brother-in-law became aware of his plight and tried to cross the flooded paddock in a tractor.
But when the tractor got stuck, the brother-in-law had to to retreat to dry land - leaving the farmer stranded with an ``uncomfortable night ahead of him''.
Westpac Waikato Air Ambulance pilot Dan Harcourt said the farmer had been cut off by a flood channel about 30m wide and 1.5m deep, where the tractor had been abandoned with water up to its engine and steering wheel.
The man decided against trying to cross the flood channel and took shelter in a barn full of "cosy little hay bales'' overnight.
The helicopter crew picked him up "in good spirits and health''.
"He was just a bit hungry and probably still a bit concerned for his cows,'' Mr Harcourt said.
"Pretty hardy bunch, the old farmers.''
The helicopter crew flew the man about 700m to his farmhouse, where he had ``a quick meal'' before heading back out to rescue stock.
"He'd gone back out to try to look after his cows and rescue cows, because they're getting washed away.''
Authorities in Waikato are continuing to keep an eye on the lower Waikato River and the heavily swollen Piako, Waihou and Waitoa rivers.
The regional council said while the rain had eased, there would continue to be heavy river flows, particularly on the Piako and Waitoa rivers, where levels were likely to match those at the 2008 floods.
Emergency management officer Greg Ryan said farmers might see surface water building up on paddocks in many areas, as land may not drain as quickly due to floodgates being shut.
"The reality is the water will take some time to work its way through the system and there is always potential for more rain to fall on the saturated catchments at some stage in the future.''
Mr Ryan advised farmers to move stock to higher ground if necessary, and for the people to be alert of road closures and other problems caused by the rain, high river levels and ponding on paddocks.
In Northland, a lightning strike north of Whangarei cut power to about 31,000 customers for about an hour this afternoon.
Two tourist couples a child who were camping at the Mangamuka Gorge, south of Kaitaia, had to be rescued after a flooded ford cut them off yesterday.
Kaitaia chief fire officer Colin Kitchen said a rescue line was set up across the ford and the campers, wet but unharmed, were helped to safety.
"We took them to the station so they could have a hot shower and we'll take them back to Raetea later to get one of their cars that's stuck in mud. Hopefully we'll find a farmer who can pull it out.''
WeatherWatch forecasters said the weather in most places would improve tomorrow and Thursday as a large high spreads across New Zealand.
- Herald Online / APNZ