Lee Fraser, who lives on Halifax Road, said the road between the town and the neighbouring market town of Hebden Bridge was submerged.
“It’s getting worse and worse, it’s been raining really heavily since last night,” he added.
“The siren went off at about 7am this morning and 10 minutes later everything started flooding.
“A lot of people are moving their stuff upstairs in their houses and the police came and closed the roads.
“It’s absolutely tipping it down, so it’s only going to get worse by the look of it.”
Another resident Rebecca Marshall said the town had been totally cut off after all the roads were closed, adding that flood water was “inches” from the top of the defence wall.
She was stuck in her home without electricity after flood waters started rising up through the floorboards.
“At the moment in our house it’s ankle deep,” she said.
“There’s about three feet of water outside our door. With no electricity we will have to move out.
“All the roads in and out of Todmorden have been closed, I don’t think we can get out of the town.”
She added that family and friends had rallied around to offer support and praised the strong sense of community in the town.
“All we can do is go up and down the road to try and make sure everyone is all right,” she said.
“We have had friends and family turn up from all over the place offering to help.”
In nearby Mytholmroyd residents were evacuated as the town was cut off by several feet of flood water.
Flood sirens alerted the town to the rising waters at about 7am on Boxing Day.
The centre of the town was completely under water, with residents worried levels would rise further as the rain continued to fall.
One resident, who did not want to be named, said a man had to be rescued after he tried to drive a Land Rover into the water.
He said: “He turned left after coming over the bridge and we just watched horrified as his car was dragged back towards us.”
The man said emergency services had to use a boat to get to the stranded vehicle before smashing the sun-roof and pulling the driver from the car.
He added: “It’s horrible. It was last flooded in 2012 and this is worse than it was back then.”
The man said most of the buildings flooded were businesses but there were a few rows of terraced houses which had been evacuated.
Helen McGarry, 43, who lives just a few feet away from the flood, said she was worried the water would continue to rise.
Mrs McGarry said she had lived in Mytholmroyd for about 13 years and had never seen the river so high.
She said: “We’re slightly concerned at the moment because, for the first time ever, the river’s actually come up to our back steps.
“So, for the first time ever, yes, I’m really worried. I’ve never seen it this bad, ever.”
Emergency services gathered in the town and a search-and-rescue helicopter could be seen circling around the town before appearing to winch someone from a house.
Cars were left abandoned in car parks, nearly entirely covered by the flood, and water lapped against the lower windows of houses, pubs and shops. A bus stop sign could barely be seen above the water.
The River Calder had burst its banks further out of the town, flooding the grounds of the Mytholmroyd Cricket Club and a nearby football pitch.
A couple of miles away, a row of bungalows next to the river and the Rochdale Canal had been flooded and the Luddenden Foot Bowling Club was also under water.
Sirens could be heard throughout the day as emergency vehicles tried to make their way through flooded roads and small country lanes turned into streams as torrents of water rushed from the hillsides and fields on to the ground below.