Some sections of the Abel Tasman and Queen Charlotte tracks are shut following damage caused by the heavy rain in the top of the south.
Department of Conservation northern South Island operations director Roy Grose said staff were still checking tracks in the region and the full extent of damage from last week's deluge was not yet known.
"Our staff are working as quickly as possible to assess and repair damage and reopen closed sections of tracks, but there is a considerable amount of work to do, and it will take time."
Grose said while they were still assessing and repairing damage, trampers could encounter slips, fallen trees and washed-out sections.
DoC had advised "caution" along the Queen Charlotte Track in the Marlborough Sounds for walkers and recommended against biking.
Meanwhile, coastal areas of the Abel Tasman track, northwest of Nelson, could be accessed by boat. Walkers could also get from Marahau to Coquille Bay.
But there was limited road access due to slips to northern areas of Abel Tasman, including the Wainui entrance, Awaroa, and Tōtaranui campground. The campground was open and could only be accessed by boat.
DoC would be contacting people with Abel Tasman hut and campsite bookings to offer refunds or change their dates.
The two popular tracks were among a number of DoC tracks and campsites in Nelson-Tasman and Marlborough affected by the severe weather. Access roads to some campsites, huts and conservation areas were closed due to landslides and other damage.
On the Heaphy Track, in Golden Bay, there was currently no access to Heaphy Hut from Kohaihai on the western side due to a slip at Crayfish Point.
The Heaphy Track could be accessed from the Brown Hut end but the section between Heaphy Hut and James MacKay Hut was already closed due to damage to bridges from February storms.
"People should take extra care and be prepared to turn back if the going is difficult or damage is impassable," Grose said.
"We're also asking people to report any damage they encounter on tracks, such as landslides and fallen trees, particularly in more remote backcountry areas which our rangers get to less often."
People could report damage by calling DoC's 24-hour number 0800 DOC HOTline (0800 362 468). DoC was advising people to check their website for the most up-to-date information.
• Abel Tasman
Open • Marahau to Coquille Bay, low tide route Anchorage to Torrent Bay, Te Pukatea and Pitt Head Loop, Bark Bay to Tonga Quarry, Onetahuti Bay to Awaroa Beach
Closed • Coquille Bay to Anchorage, high tide track Anchorage to Torrent Bay village, including Cleopatra's Pool track, Torrent Bay to Medlands/Bark Bay, Tonga Quarry to Onetahuti, Awaroa Saddle to Awaroa Hut
Open with caution • Meretoto/Ship Cove to Furneaux and on to Miners/Head of Endeavour Inlet, head of Big Bay to Camp Bay and the Historic Track to Kenepuru Saddle and road, Camp Bay to Eatwell's Lookout and on to Black Rock Campsite, Torea to Te Mahia/Mistletoe Bay, Te Mahia/Mistletoe Bay to Anakiwa
Closed • The Waterfall Track at Meretoto/Ship Cove, Miners/head of Endeavour Inlet to head of Big Bay, Black Rock campsite to Torea Saddle
Other tracks Wainui Falls Track, Golden Bay - closed Cable Bay Walkway, Nelson - closed Cobb Rd access to Kahurangi National Park – road closed due to a slip, affecting access to several huts, including Fenella, Sylvester, Balloon and Tribolite huts and Salisbury Lodge Branch and Leatham Rds. Leatham Conservation Area – closed due to slips