Video courtesy of Dave Roberts

Work is well under way to give the historic Pontcysyllte aqueduct its check-up while the canal is drained.

Engineers were due to be working today in the near empty trough that carries the Llangollen Canal across the Dee Valley along the 130 foot high aqueduct.

The plug was pulled at the structure, recently named a World Heritage Site, on Monday, sending more than a million litres of water pouring onto the River Dee below.

Crowds turned out to see the waterfall cascade from the aqueduct over two hours.

British Waterways said today there had been a slight delay in fitting the stop planks across the canal to prevent water getting into the iron trough.

“Last time the trough was drained machinery was brought in to put in the planks but this time it was done manually,” Michelle Kozomara, from British Waterways said.

“Engineers have already checked the condition of the towpath and today will be working within the trough itself.

“We hope we can start getting water back along the aqueduct by close of play tomorrow and that it can be reopened to traffic again on Saturday.”

The trough was last drained five years ago before the structure’s 200th birthday celebrations. It was built by Thomas Telford.

Thousands of narrowboats and walkers cross the spectacular aqueduct each year.