VITAL repair work to a failed valve has been carried out at remote March Haigh reservoir, near Marsden.
Vital to the dam’s safety, the valve was deemed inoperable earlier this year following a detailed inspection.
The reservoir, owned and operated by British Waterways, is only accessible by foot, over a mile of open moorland.
To conquer the complicated access and challenging weather conditions, materials were airlifted to the reservoir by helicopter.
Alex Holt, senior project manager for British Waterways Yorkshire said: “Repair work started in spring to plan and access the reservoir to remove the old valve. It was necessary to drain the water to assess the existing valve and measure for the replacement.
“Given the isolated location of the reservoir and the surrounding Site of Special Scientific Interest, the airlift was deemed the most suitable option.”
March Haigh opened in 1811 and was constructed to feed the Huddersfield Narrow Canal. Its maximum capacity can scale 71 million gallons.