There is a “massively urgent” need for investment in flood defences in Downpatrick after a crack has appeared in the Quoile Bridge, a local MLA has said.

Patrick Brown, Alliance MLA for South Down, and Sinn Fein MP Chris Hazzard both visited the historic Quoile bridge on Monday where the damage had been discovered.

Downpatrick was one of a number of towns in Northern Ireland badly impacted by flooding following bouts of heavy rain last week.

Businesses in the main street of the town were under several feet of water for days after the River Quoile burst its banks.

On Monday, the Quoile Bridge, connecting Downpatrick to Killyleagh, was closed after a crack appeared between the wall and road surface of the bridge, and a stone on one of the pillars became dislodged.

Mr Brown said the damage to the bridge is thought to have been caused by pressure from recent flooding.

“We believe that this may be linked to the recent impact of the floods from a build up of debris and toxic sludge and the pressure of the water behind that, actually causing part of the wall to pop out because of pressure at the bottom of the structure,” he said.

“As a result, the road has been closed since this morning and will likely remain closed for the foreseeable future until we can try and get to grips with the scale of the damage here.”

There has not been a devolved government in Northern Ireland for over a year due to the DUPs ongoing boycott of power sharing institutions in protest against post-Brexit trading arrangements.

In the absence of an executive and assembly, Northern Ireland Secretary Chris Heaton-Harris reallocated £15 million of funding to allow emergency grants of £7,500 to be given out and for a rate relief scheme to be put in place for businesses impacted by floods.

Mr Brown said despite the emergency funding, the need for long-term investment is “massively urgent”.

“We’ve got the 15 million there, a substantial chunk of that will be going towards supporting businesses in Downpatrick,” he said.

“But we can’t forget about the need to invest in our infrastructure urgently as well. This cannot be put on the long finger, it cannot be forgotten about because of the lack of a minister and an executive.

“This needs to be done now to protect livelihoods, to protect people and businesses in Downpatrick and indeed in other parts of Northern Ireland as well.”

Mr Brown said the large volume of traffic on the Quoile bridge, which is hundreds of years old, may have contributed to the structural damage, but that work would need to be done to both the bridge and the river to protect Downpatrick from future flooding.

“There is a substantial need to invest in trying to potentially widen the bridge to make it fit for purpose in the longer term, and also the wider issue around flood defences and protecting and cleaning up the river as well so that we don’t see this build up of toxic sludge and debris, just literally choking the river and causing this pressure,” he said.

He added: “The fact is that just because a flood happened last week, doesn’t mean one can’t happen again next week, whilst we’re still in a serious situation of not having adequate flood defences.”

Mr Hazzard said the damage to the bridge so soon after Downpatrick was flooded highlights the urgent need for review and investigation.

“For this to happen it really shows you the need now for the departments to urgently get to the review stage,” he said.

“We’re meeting with the head of the civil service tomorrow at Stormont Castle to start to begin that process to find out, are the departments like DFI rivers for example, are they now doing the investigations to identify what has caused this and what we now need to do to make sure it doesn’t happen again.

“And that has been brought into sharp focus today, by the structural damage done to the Quoile bridge.

“Again, we’re going to have a situation where key strategic routes are closed. That’s not good for local businesses and it’s not good for local ratepayers as well.”

Mr Hazzard said there had been an “underinvestment in public infrastructure”.

“If you take, for example, for the last 13 years under a Tory administration in London, our public services here have been absolutely hammered by austerity,” he said.

“There’s billions of pounds have went out of the Stormont block grant, that has meant that departments have not been able to spend the money they have.

“So that’s the sort of thing we need to see changed and that’s some of the message we will be giving to the head of the civil service tomorrow.”

Peter Mullan is a Downpatrick resident who lives a short distance from the Quoile bridge.

Mr Mullan said that his home had been badly damaged during floods, and that a lack of maintenance to the bridge and river had put his home in jeopardy.

“It ended up with my entire house was under two inches or more of water, just enough to completely destroy the furniture in my lounge, all my downstairs carpets, all my wood floors in my kitchen, the new wood floors in the rest of my downstairs and also the new wooden doors that I had fitted just a matter of a few months ago, they’re destroyed with water coming up the bottom edge.

“So I feel very strongly that this bridge and this river should have been maintained better, and because it hasn’t been maintained properly I personally have suffered.”

Storm Debi has seen strong winds hit Northern Ireland, but has not led to flooding as severe as that which has been seen in the Republic of Ireland.

Mr Mullan said there was “a certain amount of anxiety” that came with listening to the weather forecasts in the run-up to Storm Debi so soon after his area was so badly affected.