Some Interislander passengers spent the night on camp stretchers after their ferry was turned back en route to Picton yesterday because of bad weather.

Interislander general manager Walter Rushbrook said the Kaiarahi departed Wellington yesterday at 4pm with 450 passengers on board but turned back when Waka Kotahi said the road between Picton and Blenheim was closed.

The decision to head back to Wellington was to avoid passengers being isolated in Picton, Rushbrook said.

Wellington City Council spokesman Richard MacLean told the Herald the council helped to provide between 30 and 40 passengers with emergency accommodation.

Some were put in a hostel and others spent the night on stretchers at an undisclosed location in the CBD, MacLean said.

Rushbrook said the Interislander was resuming sailings this afternoon after being advised the road from Picton will reopen.

"We are working to accommodate all disrupted passengers and freight as soon as we are able. At this stage we expect to clear most of the backlog by the end of Sunday.

"We are keeping all our customers updated and we apologise for the inconvenience caused by this significant weather event."

One-in-10-year rainfall

Wellington was drenched with one-in-10-year rainfall yesterday.

A clean-up is under way across the city at places like Tawa Rugby Club, which was flooded after a stream burst its banks.

Two houses in Newlands have been evacuated because of a slip.

Roads in Wellington affected by the flooding. Photo / NZTA

The council will be assessing rural roads between Johnsonville and Mākara, which got "hammered" yesterday, MacLean said.

MetService meteorologist Rob Kerr said the region got about 100mm of rain in 15 hours ending with a downpour yesterday afternoon.

"Heavy-ish rain fell on and off for most of the day and then bang, that really super-heavy blast came through right at the end."

Kerr said it was a once-in-a-decade rainfall.

MetService has issued a heavy rain watch for the ranges of Bay Of Plenty, east of Whakatane, and the ranges of Gisborne.

A strong wind warning for Wellington and Wairarapa south of Featherston has now been lifted.

However, a strong wind watch remains in force for the rest of Wairarapa, the Tararua District, and Hawke's Bay south of Hastings until early this afternoon.

Yesterday gusts of 120km/h were recorded in the Wellington suburb of Kelburn and 135km/h on top of the Remutaka Hill.

NZTA has advised the Waihenga River bridge on State Highway 53 in Martinborough is now closed because of rising water levels of the Rumahanga River.

Motorway reopens after flooding

One northbound lane on State Highway 2 from Ngauranga to Petone reopened at 1am.

However the temporary speed limit is 50 km/h because of flooding and debris.

Kaine Thompson spent four hours stuck on the motorway yesterday and another two and a half hours navigating diversions before finally getting home to Eastbourne at 10.30pm.

"We were diverted to Ngauranga Gorge and then made our way to State Highway 58 from Plimmerton, but with other road closures and heavy traffic, it was slow going across the Haywards Hill for all of us."

Debris on Coast Rd. Image / Supplied

Thompson said when it became clear they would be stuck on the motorway for a while, they decided to watch Netflix.

As the rain eased, some children joined together and played football on the slip road while other stranded passengers took the chance to chat to one another, Thompson said.

Thompson was frustrated by what he said was a lack of information about whether there would be a diversion or an estimated time for the road to reopen.

"When a police officer says 'sorry, I don't know anything', you begin to think - well, does anybody?"

The left lane of State Highway 2 before the Petone overbridge is still blocked by flooding.

Motorists have been urged to take extra care, drive to the conditions and expect delays while crews restore the state highway network.

Hutt City Council is cleaning up Marine Dr in Eastbourne, Port Rd in Seaview, and Coast Rd in Wainuiomata.

A council spokesperson said heavy machinery was being brought in for Coast Rd, which is covered in debris in parts.

All carparks and roads have reopened and river trails will be cleared of mud tomorrow, the spokesperson said.

The council received 473 mostly weather-related calls.

Wellingtonians stranded after terrifying flight

A passenger on a flight bound for the capital last night said it was the worst flight she had been on.

After taking off from Auckland an hour late, the Air New Zealand flight was unable to land in Wellington because of the bad weather.

One passenger on a flight from Auckland to Wellington said the journey was like a rollercoaster. Photo / Mark Mitchell

"On a big plane like that... it felt like a rollercoaster with lots of ups and downs," the passenger said.

The woman, who did not want to be named, said two medical events on the flight added to the "stress and chaos" of the situation.

She claimed no information was provided to passengers about alternative arrangements and the first she knew about being rebooked was a text message from the airline.

The new flight was for tomorrow morning, leaving her needing accommodation for two nights.

Her 10-year-old daughter in tow, her phone battery low and talk of Auckland's hotels being fully booked, she went back to where she had been staying at the Grand by SkyCity.

But no rooms were free there.

"I was pretty close to a meltdown," she said.

By this time it was past midnight, but the hotel worker at the Grand rang around and eventually found the pair a room for the night.

Air New Zealand has been approached for comment.