A charity set up to tackle flooding in an area of West Yorkshire devastated by Christmas storms in 2015 has thanked its volunteers in a video message on the fifth anniversary of the floods.

Slow The Flow was launched after the towns of Todmorden, Hebden Bridge and Mytholmroyd were inundated by flooding on Boxing Day five years ago.

The charity said the coronavirus pandemic had “all but stopped” its practical work in 2020 but it had used the year to make plans for the future.

Slow The Flow is releasing a series of videos about its work on Saturday, as forecasters warned that Storm Bella would bring severe gales and heavy rain to the UK and Ireland, and residents in Bedfordshire and Northamptonshire faced severe flood warnings.

In one film, Bede Mullen, chair of the charity, said: “Today marks the 5th anniversary of the Boxing Day floods in 2015 and the reason Slow The Flow was set up.

“As a group of local residents involved in the clearing up of that devastating flood and seeing at first hand the impact it had on people’s lives and livelihoods, we knew there were things we could do immediately to reduce the impact of flooding in the valley.

“So started a journey to explore the benefits of natural flood management in the Upper Calder catchment.”

He added: “We’ve been encouraged by the volunteers who have come forward to work on our projects. We’ve worked with close to 1,000 volunteers, ranging in age from four to the mid-70s, building leaky dams, attenuation ponds, stuffing gullies and placing logs on contours of hillsides to slow the flow of water coming from the tops to the valley below.”

Mr Mullen appealed for anyone who wanted to work with the charity on future projects to get in touch and said: “Slow The Flow only works because of the support of our volunteers.”

Pennine areas in the north of England saw more than 60mm of rain fall in 24 hours over Christmas Day and Boxing Day in 2015 and residents in Calderdale were alerted to rising waters by flood sirens sounding at around 7am on December 26.

Along the Calder Valley, people were evacuated as 2,781 homes and 4,416 businesses were flooded, towns were cut off by several feet of flood water, emergency services had to rescue motorists from stranded vehicles and 100 soldiers were sent in to help.

Then-prime minister David Cameron chaired an emergency Cobra meeting in response to the widespread flooding, which affected much of northern England.

Slow The Flow was set up to look at the issue of why and how the Calder Valley floods and to look at natural flood prevention measures and solutions to slow the volume of water, which comes down the hillsides into the River Calder.

Mr Mullen said the charity has worked with the Environment Agency, the National Trust, Calderdale Council, Yorkshire Water and academics and had made “tremendous progress”, promoting and implementing natural flood management in the Upper Calder catchment, and monitoring the effects of this work, with data proving it reduces the speed of the flow of rain water into the river system.

The charity’s projects have included building more than 600 woody leaky dams at Hardcastle Crags, near Hebden Bridge.

For more information, go to slowtheflow.net