Shop stock is "just floating about" after severe flooding in Downpatrick, County Down, a business owner has said.
Nuala McCartan, whose family have had shops in the town for about 100 years, said recent events are "heartbreaking".
Along with other business owners, she has called on officials to urgently provide businesses with financial support for flood losses and repairs.
It comes after a number of towns in counties Down, Armagh and Antrim were impacted by heavy downpours this week.
On Saturday, the Department for Infrastructure (DfI) urged people to avoid using the Lagan Towpath in Belfast due to flooding in parts.
Pumping has now stopped in Downpatrick after floodwater was successfully cleared from the town centre, the department confirmed.
However, the DfI said water levels in the River Quoile were still very high so remaining water could not freely discharge into it.
Market Street and several roads in the area remain closed.
"As the River Quoile level continues to fall over coming days, flood water will then be able to drain into it and naturally recede," a statement said.
Preparations for a "substantial clean-up" are also under way by council staff so the town centre can reopen to the public.
Sandbags will also be removed and power-washing operations will commence on Sunday.
On Saturday morning, Ms McCartan was evaluating the damage the floodwater has caused to her two shops in Downpatrick.
She said they might get into one of the shops later, but thinks it is unlikely they will get into the other one.
"As far as I can see, we are still a foot of water up," she said.
"My stock is just floating about.
"It's very hard - we're a family business we've just been here for 100 years, almost - it's just heartbreaking."
Ms McCartan said the community and the emergency services have been helpful, but more is needed.
"The community are amazing - with offers of help - our phones haven't stopped - but there's so many won't get back in again," she said.
"We need help, we need help now - we need that man that signs the cheques.
"I haven't the money to put into my shop - £100,000 or £50,000, I haven't got it.
"I'm pleading: please help us."
Flooding has also caused disruption to the railway line between Portadown and Dundalk, which will be closed until further notice, Translink said.
Bus substitution services will be in place for both local services and the Dublin to Belfast Enterprise service.
After hours of pumping, the floodwater on Market Street in Downpatrick has been cleared.
Drone surveys have been done to help the agencies plan.
It has allowed the services to see that there's a substantial amount of oil floating on the surface of the water.
What's been really striking is the sense of community in Downpatrick.
There are offers of cups of tea and shop owners have gone out of their way to say to us journalists that we can use their bathroom or come in and sit down.
There is a stand at the Civic Centre supplying hot drinks and soup to all those involved in the pumping operation too.
People are helping each other in any way they can.
Once all shop owners can get in past the sandbags piled four and more high in front of their premises to assess the damage, then the real clean-up begins.
Sinn Féin deputy leader Michelle O'Neill called on Northern Ireland Secretary Chris Heaton-Harris to provide funding for emergency relief efforts as well as financial support for businesses and people affected by the flooding.
Shadow Northern Ireland Secretary Hilary Benn also wrote to Mr Chris Heaton-Harris to ask what assistance the UK government could provide.
"The UK government has already announced support for households and businesses in England which have been affected by flooding and I would be grateful if you could promptly clarify whether Northern Ireland will receive similar support and what form this support will take," Mr Benn said.
Director of Downpatrick and County Down Railway Jonathan King said damage to its buildings and stock may roll into hundreds of thousands of pounds.
Some of the heritage engines and carriages, dating as far back as 1862, are irreplaceable, he told BBC News NI.
They cannot yet assess the full damage as floodwater lingers around the museum's entrance.
'I'm very worried'
Sean Sealey is the manager of a pharmacy which was flooded in Downpatrick and has reopened for prescription services.
"The community has been amazing in helping us - we've been able to supply a full pharmaceutical service and nobody has been affected by it, as far as we know," he said.
But Mr Sealey said he is devastated for other businesses that are unable to open.
"They need money now to help them rebuild," he added.
"If they're not here on the street, I'll be the only one standing. I won't have any footfall coming in and my trade will drop - I'm very worried."
Social Democratic and Labour Party assembly member Colin McGrath said that the remaining floodwater "is exceptionally dirty".
"There are branches, tyres and obviously sewage - it could be Sunday before anyone can really assess the damage in their businesses," he told BBC News NI.
Downpatrick and Newry, in County Down, and Portadown, in County Armagh, are among the areas that have been worst affected by flooding.
A number of homes in the Portadown area have been damaged by flooding in recent days, with roads closed and transport services disrupted.
The Department for Communities is providing emergency £1,000 payments for domestic properties which have been flooded.
In pictures: Floods cause havoc across Northern Ireland
On Friday, the Northern Ireland Office said a recovery sub-group had been established to bring together civil service departments and local government.
It said this would engage with businesses affected by the severe weather and keep political representatives informed.
On Saturday night, a spokeswoman for the Northern Ireland Office Spokesperson said: "The UK government is in close contact with the Northern Ireland Civil Service regarding the severe flooding across the region.
"Whilst this is a devolved matter for the relevant NI departments, we will continue to work closely with the NI Civil Service in the days ahead."