Civil Defence teams will be out at first light assessing the damage caused by flash flooding at Waihi Beach that forced up to 50 people from their homes.

On Monday, a torrential downpour tore up roads, destroyed footbridges and brought floodwaters up to waist height.

It's believed that up to 50 people were evacuated on Monday afternoon, including elderly residents rescued by firefighters when water reached their windows.

Most evacuees found accommodation with family overnight but three elderly people and one family on holiday were put up in a local camping ground.

Western Bay of Plenty District Council Civil Defence controller Peter Watson says their teams will take a closer look at the flood-affected properties this morning.

"Our Rapid Building Unit guys are going to assess the pensioner units and any other buildings that need to be assessed as to whether they are habitable at the moment".

Peter says a welfare team will also check in with each person displaced by the flood.

The pensioner housing on Beach Road had been one of the worst hit areas and 11 out of the 19 units were flooded.

Katikati-Waihī ward councillor Allan Sole says emergency services teams were needed to help get people out.

"There were people there who were vulnerable and were having to be evacuated in a fairly deep pool of water".

Flooding on Brown Drive on Monday.

He says the flats were right beside a stream and there was nowhere for the water to go.

Sole told RNZ the streets and homes flooded yesterday, including the pensioner units, had been hit before.

Ten years ago there was a major flood in the same area and the council then allowed people to raise their homes above what they thought the water level would be, he says.

"But of course the lower areas or their garages and their sections would still have water on them."

Alan says much of Waihi Beach is low lying and houses had been built on swamp land.

-RNZ.