Severe weather warnings are in place for Buller and Westland, as well as Marlborough Sounds and parts of Tasman district, through to Thursday evening.
Heavy rain is forecast to hit the region with rivers and streams expected to rise swiftly.
After two major flooding events over the past year, it is a situation locals are all-too familiar with.
Rose Jackson has been back in her Westport home for only about four months, after being evacuated by Civil Defence in July 2021 as floodwaters inundated her property.
Jackson said it was hard not to feel anxious about the uncertainty in the days ahead.
"Apprehensive ... is the word I would use," she said.
"Not knowing what's going to happen, it could turn very nasty or it could be a big event and not come to anything. It really depends on how much rainfall we get."
MetService warnings say 150mm to 280mm could fall throughout most of Buller over the next two days.
Stephen Switalla has also just moved back into his newly repaired Westport home in April after copping flooding damage last year and further weather warnings have left him feeling frustrated.
"We got through July and I thought we were okay," he said.
"Now it's the middle of August and we get this big rain warning again.
"It's pretty upsetting when you hear it, especially with how much rainfall they're predicting."
Another Westport resident, Tania Hawken, told RNZ every weather warning was stressful and her anxiety was through the roof.
She said she spent yesterday lifting items in her garage onto higher surfaces after discovering during last year's flood that her private insurer did not cover flood damage to garage contents.
Severe weather warnings are also in place further north in Tasman and Marlborough, with a similar volume of rainfall predicted for the Marlborough Sounds over the coming days.
Along the Kenepuru Sound, Ross Withell fears the road he lives on could sustain further damage after last year's floods caused a major drop out.
"If this weather bomb comes through to anything like what's forecast, there will be more damage, it's just inevitable," he said.
Buller's civil defence team has established an Emergency Operations Centre for residents, and sandbags have been made available.
Buller mayor Jamie Cleine said the past 24 hours have been about getting ready.
"We're just putting in the necessary steps and we've got some resource coming in from outside the district," he said.
"It's just a wee bit early to drill down exactly where and what resource will be required.
"The local volunteers are stepping up to assist with sandbagging and things like that."
Nelson City Council was urging residents to check drains and gutters are clear of leaves and debris.
A spokesperson said sandbags should be considered and properties near water, or in low-lying areas, should prepare for flooding.
Tasman District mayor Tim King said Civil Defence and roading crews were making preparations go to Golden Bay where significant rain was forecast.
Heavy falls were also predicted for the Richmond and Bryant ranges and the Motueka Valley.
"If we get that very intense event in any of those locations it can have very severe ramifications. We've already had such a large amount of rainfall over the past eight to ten weeks, so the ground is already heavily saturated."
Waka Kotahi/ NZ Transport Agency said there was a higher risk of tree falls, slips, and rockfalls in these regions as the rain continues in a very wet winter.
