Updated 9.36pm: A civil defence emergency has been declared in Whanganui and the Rangitikei District.
Waitotara township has been advised to evacuated this evening due to rising river levels and the prospect of flooding after today's heavy rain.
Mayor Annette Main reports some people will be asked to leave their homes.
She is urging those people to listen and leave as soon as possible.
The Government has offered Whanganui help should it need it.
Civil Defence Minister Nikki Kaye reports the state of local emergency enables about 100 people living near the Whanganui River to be evacuated.
She has said civil defence emergency management responders, including emergency services and the army, are supporting the evacuations.
The Ministry is monitoring the situation and is ready to coordinate support if necessary.
Kaye adds she will be regularly briefed through the night, and her thoughts are with everyone affected.
Further evacuations are under way in Putiki (Takarangi Street). There have also been evacuations in London Street and Alexander Street following extensive ponding in Peat Park and the surrounding area. Property owners in areas of Anzac Parade and Taupo Quay are being notified to evacuate. Army personnel will assist with the evacuations.
Manhole covers in Kowhai Park have been lifted to allow stormwater and sewage to spill into the park to lessen the impact on nearby properties in Anzac Parade and in the Matarawa Stream catchment. The public must stay out of the park due to the danger of open manholes.
Sewage and stormwater spills are being reported throughout the district so all flood waters should be considered contaminated. Please keep away from creeks and other flooded areas. Drinking water quality is not affected.
The city water supply pressure has been reduced and residents are asked to conserve water but the water is fine to drink. Power is out to the Kai Iwi bores – power is expected to be restored to Kai Iwi this evening.
There may still be isolated pockets of power outages. Please contact your energy supply company to report any outages.
Rangitikei District information
Residents are being evacuated from the isolated village of Koitiata, where there are 140 homes.
Rural fire crews are working with the Army to get people out on unimogs.
Incident controller Ross McNeil says steps are currently being taken to widen culverts and divert the flow around the village.
A welfare centre has been set up at the Memorial Hall in Marton, with the help of Red Cross.
There is also a state of emergency in Whanganui, where residents in Anzac Parade are being evacuated.
The Whanganui River is currently flowing at a height of 15.5 metres at the Pipiriki monitoring site as rain continues to fall.
This is expected to flow through to Town Bridge at around 1am and will coincide with the high tide.
All the river systems in the region are under observation and this monitoring will be continue throughout the night.
Steady rain causes flooding across the lower North Island
Low-lying parts of the Manawatu town of Feilding are under water today.
Homes have been evacuated in Queen Street, where floodwaters are lapping at the doors of houses at the south end.
Manawatu mayor Margaret Kouvelis said residents are being kept warm and happy with their pets, at the town's evacuation centre.
There's been no let-up in the rain but there's no wind, so the rain has been driving straight down for more than 24 hours.
Flooding has now closed State Highway 54 in the central North Island.
It means the only north to south route open is State Highway 2 between Wellington and Hawke's Bay.
Road Transport Forum chief Ken Shirley says it's incredibly disruptive, especially for freight trucks.
"What we've got here is the whole bottom of the North Island, Wellington is effectively cut off from State Highway One to the north, so the only linkage is through the Wairarapa and that can be very disruptive."
There's also no longer a detour available for the closed section of State Highway 1 between Bulls and Hunterville.
The Transport Agency is asking people not to travel unless it's essential.
Power has been temporarily restored to 4500 Whanganui properties after floodwaters earlier inundated a substation.
But Powerco are warning customers it would have to be switched off again for about four hours this afternoon to clear debris and trees from high voltage lines affecting about 3000 customers in the Westmere, Kai Iwi, Whanganui, St Johns and Brunswick areas.
Heavy rain continues to cause power supply problems in several Taranaki areas.
Kapiti District Council has activated its Emergency Operations Centre, with heavy rain causing widespread flooding problems.
There's significant surface flooding in the Te Horo and Ōtaki areas.
A small number of people have voluntarily evacuated their homes.
Waikawa Stream Bridge has been damaged in the flooding. It means State Highway One is closed both north and southbound at Manakau near Levin.
The New Zealand Transport Agency is hopeful it can reopen the Waikawa Stream Bridge at Manakau on State Highway 1 later today.
Inspector Marty Parker said even though it's the weekend, the road carries a lot of traffic.
"We've still got commercial vehicles, trucks going through, tourists going through, so they're going to have to look for alternative routes or wait it out for the next couple of days."
Drivers will have to use State Highways Two and Three instead.
The bridge at Ringawhati Road in Ōtaki has been washed out, and the water main has been severed - the council says a number of households may be without water.
Residents are also urging people to check on their neighbours.
Sewage in New Plymouth
The clean-up of the New Plymouth CBD has been going well and it will be business as usual tonight, with resteraunts, hotels and other entertainment venues open.
People are being advised to avoid waterways in New Plymouth, after heavy rain has caused raw sewage to overflow.
Water and Wastes manager Mark Hall says people shouldn't be swimming, surfing or collecting shellfish, or have any contact with local streams.
The stormwater pump station at Waitara has also been activated, and is pumping water out of the town centre.
Huatoki Plaza in New Plymouth is closed because of flooding.
Slips in Whanganui
Wanganui District Council are keeping a close eye on the town's waterways as catchments from the Whanganui River are rising heavily.
Evacuations this morning in Whanganui, where slips are threatening seven homes.
The council's emergency centre has been activated.
Wanganui Council's Cass Alexander acknowledges houses backing onto the stream are the biggest concern.
"We've advised people to secure any property, make sure their pets are okay because properties that back onto that stream are likely to be flooded or already have been flooded."
Emergency Manager Matthew Smith has said the Red Cross is on hand at homes threatened by slips in Putiki.
"Putting them into a Civil Defence welfare centre that we've set up, basically so we can get them out of the rain and keep them warm."
Matthew Smith said there's also flooding on Anzac Parade in the city, and in the Peat Park area.
"Rain was predicted for the rest of today, and of course with the ground already sodden it won't take much more rain for slips to carry on through the day."
The Matarawa Stream is expected to reach 11.3 metres after six o'clock tonight. The Council has evacuated 14 houses so far and is set to make the next evacuation decision later this afternoon.
4500 customers are without power in Whanganui, because of flooding at a substation.
Powerco spokesman Dean Stevenson says alternative supply routes are being used wherever possible.
Another 360 properties at Whakamara in South Taranaki were cut off last night.
A slip on the Tangahoe Valley Road is preventing workers from accessing the network and making repairs.
Sewage in Whanganui
Hygiene is becoming an issue for Whanganui residents as concerns flood water now contains sewage.
Wanganui Council's Cass Alexander has asked people need to stay indoors out of the water and not head out in their vehicles to look at flooding.
She says they would like to hear from people who come across slips or more flooding - their number is 06 348 0103.
Weather heading North
The heavy rain is easing in the central North Island, but MetService is warning the bad weather is heading north.
Another 70 millimetres of rain is possible in the northern Tararua Range, Horowhenua and Taranaki today, and 120 millimetres could fall in the central North Island high country.
Further north MetService says rain is likely to lead to surface flooding, slips, and rapidly rising streams and rivers.
Up to 150 millimetres is likely between now and early tomorrow in eastern Bay of Plenty and Gisborne.