A stunning time lapse video shows the UK's deepest lock being dredged for a spring clean.

Water levels from the 20ft deep Tuel Lane Lock in Sowerby Bridge, West Yorks., can be seen dropping dramatically.

And volunteers from the Canal and River Trust can then be seen in photographs clearing the lock floor of debris and leaves.

Richard Parry, chief executive of the Canal and River Trust, said: "Still used and navigated by boats just as they were hundreds of years ago, today’s canals have also become vital places in our urban and rural communities providing crucially important habitat for endangered wildlife and vital places for people to experience nature."

"With the nation’s canals used and enjoyed by more people than ever before, together with the constant threat of climate change, these historic places need constant care to look after them. "

"We need the support of the community and conservation-minded people to help ensure that these precious places are handed onto future generations."

Vessels that use the lock are raised to more than the height of a double decker bus.

It is one of the few locks that boaters cannot operate themselves, and must be assisted by the lock-keeper due to its height.

It was built in 1996 as part of a restoration of the canal, and replaced two Victorian locks to enable the canal to tunnel beneath a road for a more efficient route.