Widespread flooding in Tokomaru Bay on the East Coast has forced some families to evacuate and roads to be closed as Civil Defence declares it too "dangerous" to travel.
State Highway 35 is now closed both north and south of the East Coast town as police and Fire and Emergency NZ crews help locals.
The Karakatuwhero River, north of Te Araroa, has flooded, as has the Wharekahika River.
There was now "widespread surface flooding" and Tairāwhiti Civil Defence was urging people to stay home and avoid any travel.
However, Civil Defence said the water appeared to be receding and the worst of the weather was heading offshore.
"We're working with Police and Fenz to check in with families and their homes.
"We advise the community to take care and avoid travel. Conditions will be dangerous for some time.
"Some families have self-evacuated and we're working with those families along with Police and Fire and Emergency.
"Please avoid unnecessary travel."
Meanwhile, MetService has issued a warning of snowfall hazards in the South Island from 3am tomorrow.
Snow flurries are expected to accumulate on the Lewis Pass above 900m and up to 1cm of snow could land near the summit.
Snow is also expected on Porters Pass between 3am and 8am, also above 900m, but little is expected to get on the road.