The central North Island is bracing for flooding as the torrential rain hammering the central plateau shows no sign of easing.
The wild weather yesterday caused flooding in Nelson and Westport before moving up the country today, causing slips and flooding in the Ruapehu and Taranaki districts.
Flood warnings are in place in Wanganui and Waikato, where authorities are keeping a close watch on rising river levels.
WeatherWatch head weather analyst Philip Duncan said heavy rain was starting to ease in Northland, Auckland and Taranaki but had not eased in parts of the central North Island all day.
"The high that last week worked for us by delivering frosty mornings and blue skies is today working against us by holding up this heavy rain over the North Island.''
Mr Duncan said heavy rainfall in the central plateau would cause significant run-off into the Waikato and Whanganui rivers, which were both expected to continue rising overnight.
Environment Waikato said the rain was expected to cause flooding of the Waipa River and catchments on the region's west coast.
"We're not expecting any major disruption as a result of the rain, but people do need to be alert to the potential for flood plains to be inundated, general surface flooding and potential problems with road access due to slips.''
Farmers have been urged to monitor the latest forecasts and move stock to higher ground if necessary.
Horizons Regional Council emergency manager Shane Bayley said Whanganui River was expected to peak at 10.5m at Pipiriki later tonight.
That level is lower than an earlier forecast which predicted the river would reach 12.5m - its highest level in more than a decade.
Mr Bayley said the council would continue to monitor the situation overnight.
Wanganui District Council emergency manager Max Benseman said the Whanganui River level was expected to peak at 7.5m at the city bridge between 7am and 9am tomorrow.
Kowhai Park has been closed and some surface flooding was likely on Whanganui River Rd and Kaiwhaiki Rd.
Flood warning signs would be erected and drivers have been urged to take caution.
Police and fire services said they had not received any major weather-related callouts this morning, but urged motorists to take care.
Some roads in and around Ohura township in the Ruapehu district were flooded this morning, with a slip closing part of Waitaanga Rd and flooding closing parts of Ohura Road.
Police closed State Highway 3 in North Taranaki this afternoon after a slip 200m north of Awakino, about 90km north of New Plymouth.
The slip had blocked both lanes, making the road impassable.
Meanwhile a secondary front was now racing up the South Island's already sodden West Coast, bringing more heavy downpours to Hokitika, Westport and Greymouth.
The main highway between Greymouth and Christchurch remained closed today after an early morning slip closed SH73 between Arthur's Pass and Springfield.
New Zealand Transport Agency West Coast area manager Mark Pinner said rocks were still coming down around mid-morning.
"It's still moving and that's our concern.''
He estimated 600 cu m of debris had been dislodged on to the road.
Contractors had been hoping to reopen a single lane today, pending a geotechnical engineer's assessment.
Roads reopened elsewhere in the region this morning, but SH65 between Springs Junction and Murchison remained closed so contractors could check the safety of a flooded bridge.
Mr Pinner said the worst affected areas were in Buller but the weekend flooding was widespread across the West Coast.
He advised motorists to be careful when driving as soil drying out over the coming days could lead to further slips.
Forecasters say there is a respite from the foul weather in sight.
MetService meteorologist Daniel Corbett said the wet weather was just about over, with a high moving across New Zealand from tomorrow bringing settled weather to most places for the rest of the week.
"Some parts of New Zealand have had a lot of rainfall over the last few days, and this will give them a chance to dry out a bit.''
Mr Corbett said there could be some cloud at times with some fine blue sky days.
Clear skies and light winds at night could bring frosts and possibly some patchy fog in sheltered places. There could be some showers in the east from Northland down to Gisborne.
WeatherWatch's Mr Duncan said the high moving in from the Tasman Sea would bring mostly dry weather and more average temperatures to the country for the rest of the week.
- Additional reporting: Nicholas McBride of the Greymouth Star