The Transport Agency says the storm-damaged Thames Coast Road is unlikely to be reopened today.
Heavy rains and strong winds caused havoc across the country, with one woman killed in Rotorua after a large oak tree came down on her vehicle, while most of the Coromandel Peninsula was hit by flooding and numerous road closures.
Transport Agency system manager Karen Royt said whole sections of State Highway 25 had been severely damaged or washed away altogether by sea surges.
She said seven crews were repairing the road with a view to getting at least one lane open.
In the meantime, it remains closed between Tararu and Manaia, except for residents between those two places.
All other state highways and council roads around the Coromandel Peninsula are currently open.
Authorities responding to the widespread flooding in Kaiaua on the western side of the Firth of Thames say the community is extremely resilient and are coping well with one of the most devastating floods they have seen.
The local civil defence controller, Steve Fabish, said he was able to give residents an update at a public meeting earlier this afternoon.
He said the East Coast Road through Kaiaua was now open although down to one lane at its northern end.
He said clean-up crews clearing debris from driveways.
Meanwhile, a young Hahei man took matters into his own hands to help the storm relief effort, delivering enough sand to make more than 500 sandbags for Thames Coast Road residents.
Brando Yelavich, also known as Wildboy, said he got a Facebook message that people needed help and didn't hesitate.
"It was my day off so I might as well go and help and drove my truck over the hill and filled it up with sand. The road was closed but I knew that my truck could get through.
"Went and helped all the people that needed sandbags for the rest of the storm that was coming on the next high tide."
Mr Yelavich said many people in the area helped the relief effort.
Power still out for thousands
Thousands of North Islanders are still without power.
Vector in Auckland said isolated pockets of the city were still being restored and would continue to work through the night and into tomorrow.
Meanwhile, there are also a number of outages around the Tauranga, Thames, Bay of Plenty Waikato and Hauraki regions.
Powerco said there were currently 2000 customers without power, while 9000 properties were without power at the peak of the storm.
Operations Manager Phil Marsh said they were hoping to get the majority of the power back on by tonight, with staff out at first light tomorrow to restore supply to those remaining properties.
How exactly did the low affect NZ? This annotated loop of radar and winds shows the low crossing NZ from Thursday through to today. ^TA pic.twitter.com/SDoFQskOSU— MetService (@MetService) January 5, 2018
Some of the of the worst hit spots were along the coast in the Firth of Thames, especially in the Coromandel and along State Highway 25 Thames Coast Road, particularly around Whakatete Bay.
The state highway was badly damaged and many houses flooded during the storm remain without power.
Red Cross emergency teams have been on the ground today.
Thames Coromandel District Council said the weather eased overnight and there were no further reports of flooding, slips or road closures.
It said all roads were open today but the Thames Coast Road (SH25) was only open to residents and emergency vehicles.
Any traffic leaving the peninsula is asked to do so through Whitianga and Tairua.
The Pauanui water treatment remains closed due to sediment in the water and residents are asked to conserve water. There were no issues with wastewater contamination, the council said.
Whangamata residents are being reassured their water is fine to drink, despite its turning yellow after yesterday's storm.
The Thames Coromandel District Council said one of the town's water sources was higher in iron oxide but that wouldn't cause any health issues.
In the South Island, State Highway 1 has reopened after slips due to the weather closed the road north and south of Kaikōura, although a truck crash again closed SH1 north of Kaikōura for several hours on Saturday afternoon.
The worst of the wild weather had passed by today, the MetService said.
Visible satellite loop (10am-2:40pm) of the #subtropicalstorm showed it moving onshore a short while ago in the Waikato (Waitomo District) -- fascinating meteorological display & busy weather for NZ! pic.twitter.com/IxrH9ZY9ET— NIWA Weather (@NiwaWeather) January 5, 2018
MetService meteorologist Tom Adams said the heavy rain had eased overnight, and the north easterly winds which had hit the Coromandel Peninsula particularly hard had switched to the south west.
"Things are able to start drying out, things have eased.
"The good news for the whole country, including the Coromandel, is the worst is now over."
Mr Adams said weather stations on the hills of the Coromandel Peninsula received more than 150mm of rain between midday Thursday and 7am this morning.
Residents in Te Puru, just north of Thames, say some homes in the area have around half a metre of sand a debris built up around them.