A further onslaught of wet weather in the South Island has prompted flood warnings to campers and farmers in South Canterbury.
MetService has issued a severe weather warning for the Southern Alps as a west to southwest flow spreads across the country, bringing with it heavy rain and gales this week.
Rain, stronger winds and gales would hit central parts of the country and exposed parts of Northland and Auckland before moving to the South Island, MetService spokesman Ramon Oosterkamp said.
By tomorrow, heavy rain was expected in the west, and gale or severe gale northwesters in the east.
"The western and alpine areas of the South Island may see another period of heavy rain, which may pose problems to those areas affected by the wet weather of last week," he said.
In the 24 hours from this evening, some 300mm of heavy rain was expected to fall in the same catchment areas of the Southern Alps that were drenched early last week.
The deluge has prompted Environment Canterbury to issue flood warnings, while the New Zealand Transport Agency (NZTA) will close part of State Highway 94/Milford Rd from tonight and all day tomorrow as a precaution against rock fall.
Environment Canterbury southern region duty flood control manager Chris Fauth said while lake levels had mostly peaked or were receding after last week's deluge, many rivers in the upper Waitaki catchment remained at higher than normal flows.
Waitaki catchment levels were likely to increase again from tomorrow, while the rain was also likely to cause a significant increase in flow in the Rangitata River.
"All campers, fisherman and recreational users of both the Waitaki and Rangitata catchments need to be aware of the potentially worsening situation and alter the way they camp and use the lake and rivers accordingly," he said.
Campers, farmers and other landowners in the area should monitor the situation closely.
People on the plains should also stay alert, even if the weather was fine, because rivers could still become unsafe as floodwaters flowed rapidly downstream.
NZTA Southland state highway operations manager Peter Robinson said the Milford Rd would be closed between the Homer Tunnel and Murrell's Bridge from 7pm today due to the heavy rain forecast in the area.
He expected the road would reopen on Thursday and remain open for the rest of the week, but what time it reopened would depend on weather conditions in the morning.
The road has been closed every night from 7pm to 7am since late November because of safety concerns over rockfall risks.
The nightly closures would continue until late January while NZTA worked to manage the risks.
Heavy rain in Westland, Nelson and Buller last week washed away a bridge and caused holiday traffic mayhem.
The wild weather washed out a section of Wanganui River bridge at Harihari, south of Hokitika, on Wednesday, forcing holidaymakers to make lengthy detours.
The reconstructed bridge was reopened yesterday.
The heavy rain comes after scorching hot weather last week, which weatherwatch.co.nz said was among the hottest on record in parts of the south.
Temperatures in the mid-30s were recorded in several areas including Dunedin, Mosgiel, Hanmer Springs and Murchison.
Meanwhile, rough seas have affected those further north.
Two men had to be winched from the Firth of Thames last night after their dinghy flipped over in stormy conditions, while a 71-year-old man was hit on the head by a dinghy which was picked up by high winds in the Nelson region yesterday.
Also yesterday, the body of a 41-year-old local man was found hours after he was swept away at the Motu rivermouth near Opotiki, where he had been fishing with friends.
Police reminded the public about the dangers of high water levels and stormy surf, urging people to take every safety precaution including wearing life jackets.