Lower Black Moss Reservoir was completed in 1903. Upper Black Moss Reservoir was built in 1804. They were built to supply water to Nelson and Barley.
The reservoirs are owned and managed by United Utilities. They are not currently used to supply drinking water. They are compensation reservoirs; used to put water back into the environment to make up for that taken out for drinking.
In 2011 a 17th century cottage was unearthed near Lower Black Moss Reservoir while United Utilities were working on a construction project.
The skeleton of a cat was found bricked into one of the walls. It was probably put there to protect the occupants from evil spirits. There was speculation at the time that the cottage could have belonged to one of the Pendle witches.
The cottage was reburied in 2012 to prevent weather damage and protect it from treasure hunters. Archaeologists determined that the cottage was more likely to have been the home of a weaver than a witch.
Aitken Wood and the Pendle Sculpture Trail are situated next to Upper Black Moss Reservoir.
There are good views of the reservoirs from Pendle Hill.