The woman was trapped in her vehicle by flood water, following a thunderstorm and heavy downpours early on Thursday morning.

The most affected areas include the Tullybrannigan area, Burrendale Road and the Mourneview estate in the town. Sandbags were put in place and home owners were unable to get out of their houses before the flooding started to subside in the afternoon.

The Fire Service has also been responding to calls for help in Castlwellan, Kilcoo and Newry.

"Local Fire Crews rescued a female from her car trapped in flood water on the Burrenbridge Road in Castlewellan, and continue to assist with other flooding related incidents in the area," a Fire & Rescue Service spokesperson said.

"We have deployed our Specialist Rescue Team from Belfast into the area to be immediately available to deal with emergency incidents.

"We are working closely with our colleagues from other emergency services and statutory agencies to assist members of the public."

Down Council has put its emergency plan in operation in Newcastle and has placed other towns on high alert.

This was very worrying time for, particularly the elderly and those living alone - although thankfully no one has yet to be evacuated from their homes.

Margaret Ritchie, South Down MP

Local Alliance councillor Patrick Clarke described the situation - which follows last week's flash flooding which saw more than 600 homes damaged in Belfast - as "absolutely horrendous".

"It would appear no lessons have been learnt from what happened in Belfast last week," he said.

"Representatives on the ground from the Water and Roads Service are working hard to resolve the situation, but people have found difficulties in using the Flood Line to report problems which is absolutely unacceptable."

Mr Clarke added: "The Northern Ireland infrastructure simply cannot cope with the rain that fell this morning. The majority of manhole covers were either blocked or not working correctly.

"On several occasions, I had to help constituents remove the manhole covers and attempt to clear the drains themselves, in a bid to try and save homes from suffering complete devastation.

"The situation is completely unacceptable."

South Down SDLP MP Margaret Ritchie has said that the longer term issues need to be examined.

"I will be organising an urgent round table meeting with all agencies to ensure an effective and efficient strategy is put in place for Newcastle," she said.

"Agencies need to put in place measures to ensure this does not happen again, particularly as due to the climate change and varying weather in Northern Ireland, it is difficult to predict when downfalls of this nature will happen.