As the clean-up begins for many following this week's severe weather, the state highway network across the top of the South Island remains disrupted, with a number of closures still in place on Sunday morning.
"Recovery and assessment work is continuing," Waka Kotahi said in a statement.
"However, because of the extent of the damage caused, it will be some time before the links between Nelson and Blenheim on State Highway 6 and State Highway 63 are restored.
"An update on their status will be provided on Tuesday, 23 August."
SH6 Nelson to Blenheim is closed between Hira and Rai Valley due to flood damage, and SH6 Rocks Road is closed from Haven Road to the Tahunanui intersection because of slip risk. SH63 Renwick to Saint Arnaud closed because of flood damage.
Marlborough Roads Manager Steve Murrin said that while an assessment will take place on Tuesday, it is "unlikely" either SH6 via Rai Valley or SH63 via Wairau Valley will reopen any time soon.
"There is massive damage to SH6 particularly over the Whangamoas and at Atawhai and Collins Valley so our big push will be to get SH63 open," he said, adding that there was still a metre of water across SH63 in places.
Waka Kotahi added later on Sunday that the closure of SH6 Rocks Road will also remain in place until at least Tuesday.
Mark Owen, Acting National Manager Maintenance and Operations, said: "We will update the road's status on Tuesday, 23 August, at the same time as we provide updated information on the closures of State Highway 6, Nelson to Blenheim, and State Highway 63, Renwick to Saint Arnaud."
"We appreciate these closures are frustrating for road users and residents, but the nature and extent of the damage mean safety has to come first. These roads are currently not safe and therefore not open to public access."
A number of other roads in the area are operating with reduced lanes or with traffic management in place.
"While the bad weather has eased, the need for road users to take extreme care remains," Waka Kotahi said.
"The weather has caused extensive damage, and drivers must drive to the conditions. Contractors are working hard to restore access to affected areas. This means roadworks and delays will affect travel times. Road users are urged to check road conditions before travelling.
"Motorists are still strongly advised to avoid travel or keep to essential trips only in areas still covered in flood waters and debris around Tākaka, Nelson and Blenheim."
In an update on Sunday morning, Marlborough District Council said Civil Defence Emergency teams were continuing to assist with delivering essential items to isolated communities in the area.
The council added that "Marlborough Harbourmaster boats will be out on the water today in Queen Charlotte Sound to check on residents and conditions", and "people continue to be advised to treat all surface water as if it is contaminated" with sewage.
Marlborough residents affected by flooding who are on their own water supply are advised to boil water before drinking it.
And Nelson Tasman Civil Defence posted an update to Facebook on Sunday morning, saying "there were no new significant weather incidents or evacuations in Nelson Tasman overnight".
"We are working as quickly as we can to get people home safely and so far have looked at around half of all impacted properties.
"Please wait to hear that your area has been inspected before returning home – if we haven’t checked homes properly, the land could still be unstable.
"Please go to Saxton Stadium if you need help. Not just food and money, but emotional support too. WE ARE HERE TO HELP. This has been an incredibly stressful time for those effected."
A meeting for people in the Nelson Tasman region who have been evacuated or have had their property impacted was held at Saxton Stadium at 2.30pm on Sunday.
At the meeting, Nelson Tasman Emergency Management said they have records of 570 properties impacted, with 264 assessed as "white", 11 assessed as "yellow" and nine assessed as "red".
"White" means the homes are safe for residents to return to, "yellow" means a house can be inhabited but it needs extensive work, and "red" means a house cannot be re-occupied.
They endeavour to assess all remaining impacted properties by 5pm Monday, and for Geotech and building officials to finish their inspections of coloured placard houses by 5pm Friday.
The recent torrential rainfall in the region has been described as a one-in-100 year event by Nelson's mayor.
More than 500 properties from the Nelson Tasman region were evacuated.
And in Wellington, the wet weather continued to cause disruption.
A number of road closures are in place around the capital, with Wellington City Council asking members of the public to "please avoid slip areas where possible for safety reasons".
"City Council staff and contractors are still working on about 130 live incidents around the city today as the wet weather and wind continues to cause problems with landslips, flooding and trees down," the council said in a statement.