Nelson Tasman Civil Defence has confirmed the recent flooding is the worst in almost 150 years.

The region has been battered with a barrage of downpours over the last week, damaging homes and farmland, and causing slips.

Communities met on Saturday to discuss the recovery, with about 50 people attending a meeting at Riwaka Memorial Hall.

Controller Rob Smith said it was the biggest flood since 1877, when a hole was put in a rock up near Ngatimoti after the floods. This week's deluge was up to a plaque placed there.

Civil defence urged people to take care when assessing their properties for flood damage.

The region remained under a state of emergency, after being battered by rain and flooding.

Crews were out checking properties across the region, with 42 staff on the ground around Brooklyn and Wakefield to build a picture of what they needed.

Close to 650 properties had already been assessed, with 90 of them provided with information to help them reach out for support.

One property was red-stickered and another 13 were yellow-stickered, after floodwaters swept through them.

Response controller Rob Smith said full recovery costs would take time to work out, but they would need government support to help with the years-long clean-up.

"A lot of the landowners in the Motueka particularly went through the 1983 flood, so they know the time that that took to recover from," he said. "That was a big valley floor flood.

"This was half a metre to a metre higher. This was a much bigger flood."

The horticulture and agriculture industries were hit hard, with floodwaters tearing through properties, prime pasture and farmland, and leaving silt, muck and debris behind.

About 200mm fell over a 48-hour period across a broad part of the region, which then faced more rain this week.

Two community meetings were being held at Riwaka Memorial Hall and Ngātīmoti Hall on Saturday, so people knew who to contact for support and could speak directly to government services.

"We want to see it as a seamless response," he said.

"This is not just a Nelson Tasman issue. This is important to the country, so trying to get people back on their feet as soon as possible."

The ground was so saturated and unstable that people might notice ground cracks, movement or strange seeps, he said.

"Please be super careful out there, so the rivers have changed, the trees are piled on top of each other, there's holes on the banks," he said.

"When you're out and about, and we know… we encourage people to go out and sort their situation out, but just be super aware of your surroundings, when you're doing that."

He encouraged affected residents to ask for help.

"We know our rural folk are really resilient, and they just got in and sorted stuff out, but it is actually OK to ask for help," Smith said.

"You know that old maxim about, 'If you don't ask, you don't get', there are opportunities out there to get support or to get noticed, so we really want people to do that."

He wanted to thank the emergency services and many volunteers for stepping up and supporting the region and its communities.