Heavy machinery was used to clear the roads before the travellers could drive out, said New Zealand Transport Agency spokesman Ewart Barnsley.
Among those stranded was Rangiora woman Alana Hands, 31, who was with her two young children and her father.
The family set out for the West Coast about 2.30pm and should have reached Westport about 6.30pm. Instead, they arrived almost five hours later. Gale-force winds slowed their utility vehicle down through the Lewis Pass and from Springs Junction the rain was torrential.
"You couldn't go faster than 50km/h, it was too heavy to see," Ms Hands said.
About 6.40pm, at Fern Arch in the Lower Buller Gorge, a big slip blocked their way.
"We couldn't even see with the wipers going."
They tried to go back, but flooding had inundated the road at Hawks Crag, Ms Hands said.
They waited until the rain eased and the flooding receded, then drove back to Berlins, where other motorists told them the road to Inangahua was blocked by two more slips.
"We just parked up at Berlins - there was about eight cars - and just waited and waited."
About 10pm lights appeared on the horizon. Ms Hands flashed her lights as they passed and a Downer vehicle stopped.
Behind it was a loader and a police car, looking for a pregnant woman who was not among the motorists at Berlins.
The motorists were told they could proceed with caution towards Westport. It was a scary drive, Ms Hands said.
"The drains were all full and flowing like streams and there were big rocks. The other concern was, you were worried a slip or rocks was going to come down on top of you."
Four trampers spent a cold and wet night stranded in the Kahurangi National Park when they were cut off by a landslip.
The Nelson Marlborough Rescue Helicopter was able to fly into the area yesterday morning and winch the group, who had camped for the night above the slip, to safety.
Severe weather caused widespread flooding and travel chaos on the West Coast over the past two days, with more than half a metre of rain in some areas. The winter-like weather brought down a vital bridge and fibre-optic cable on State Highway 6, just north of Harihari, cutting off communication for about 1000 residents.
Floodwaters prevented structural engineers from inspecting the bridge yesterday.
"Teams of contractors are working 15 hours while there's daylight to clear the flood debris and divert the river. Once water levels drop we can get in quickly to inspect the bridge and then start rebuilding that section of the highway lost in the flood," Transport Agency spokesman Mark Pinner said.
The agency was hoping to have a clearer picture today on how long it would take to reopen the road, although it was expected to take days.
The West Coast road via Lewis Pass through Murchison also had to be closed, forcing travellers to make a seven-hour detour around Blenheim and Kaikoura to get to the east coast of the island.
State Highway 65 from O'Sullivans to Springs Junction remained closed last night by flooding. State Highway 6 in the upper Buller Gorge had been closed by floods but reopened yesterday afternoon.
Snow fell on the Lindis Pass in Otago overnight yesterday, forcing travellers to abandon their vehicles near the summit. But MetService forecaster Peter Kreft said the weather had generally settled down and New Zealand now had a ridge of high pressure sitting over it.
Weekend weather:
Today: North Island generally fine apart from morning cloudy periods and some isolated showers in Taranaki.
Temperature high in Auckland of 22C and 12C overnight.
South Island showers clearing north of Fiordland this morning, but drizzle in Westland this evening. Possible thunderstorms and hail south of Banks Peninsula.
Tomorrow: North Island fine throughout, with temperature highs of 25C in Auckland and 26C in Waikato.
South Island mainly fine and very warm with a few showers in Westland and Fiordland. Colder temperatures also, with a high of 13C expected in Queenstown.
Sunday: North Island fine apart from cloudy periods in the north and west.
South Island has a few showers spreading from the south and becoming cooler.
Source: MetService
- APNZ, Westport News