Tasman District Council says residents near the Motueka River from Tapawera to Riwaka should be prepared to evacuate quickly if necessary because of rising river levels.
The council says people should stay with friends or whanau if they need to leave, or go to the Motueka Recreation Centre on Old Wharf Road if it is safe to do so.
This warning comes after Marlborough Emergency Management issued a 'be ready to evacuate' warning for residents in the Lower Terrace area in Renwick.
The council's hydrology team had been modelling on a stopbank at the confluence of the Waihopai/Wairau rivers and determined the bank had become unstable, Incident Controller Richard MacNamara said.
This poses a risk of breaking and flooding lower parts of Renwick township (Lower Terrace) and surrounding land adjacent to Gibson's Creek and up to the Waihopai/Wairau confluence.
"We are taking the precaution of advising residents of Lower Terrace to be prepared to evacuate," MacNamara said, adding that the Defence Force, FENZ and Marlborough's Rapid Response team would be door knocking in the area.
Floodwaters have closed SH1 out of Picton - the key transport route for Cook Strait ferry traffic and freight.
The road is closed between Tuamarina to Mount Pleasant, and there are no local detours.
Kiwirail said there are no disruptions or implications for Interislander ferries due to the state highway closure and all ferries are running to schedule.
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The Appleby Bridge Recreation Reserve near Richmond earlier today. Photo: RNZ/Mark Papalii
