Protesters re-launched their fight to save a “secret seaside” with a picnic on the shore.
Dozens of people turned out on Sunday to show their support for protecting Cupwith Reservoir.
The little-known beauty spot, off New Hey Road above Slaithwaite, could be drained after the Environment Agency branded it “dangerous.”
The reservoir’s owner, Dartmouth Estate, was refused planning permission to reduce the amount of water from 25,000m� to 10,000m� and carry out a series of repairs and improvements.
But the landowner has appealed against the decision, meaning the Cupwith Reservoir Action Group (CRAG) has struck up a new campaign.
At the picnic protesters were entertained by jugglers, stilt-walkers and a ukulele player.
They picnicked on barbecue food and homemade bread and cakes on the sandy shore.
Campaigner Pat Jones, who lives nearby, said: “While we enjoyed ourselves this is a serious matter.
“The plans would turn this lovely reservoir into a muddy puddle.
“People have enjoyed the area for years. Many of the people who turned up on Sunday knew nothing about the protest, they just turned up to enjoy the place as people have done for generations.
“They have been dismayed to hear that the beauty of the reservoir may be destroyed.”
Pat and another campaigner Lesley Hedges walked into the middle of the reservoir to show the plans were based on a false assumption.
It was claimed the reservoir averages more than two metres in depth but the two women could find nowhere much more than waist deep.
They said that meant the average depth was less than one metre.
The reservoir is one of several high in the Pennine hills built in the 19th century to ensure a reliable flow of water for the mills further down the watercourse, and is part of the historic fabric of the Colne Valley.
