Taking the steep footpath from Todmorden to Langfield Common during winter, walkers will often find a snow-dusted landscape, which levels out to a high plateau. On the moor, Gaddings Dam comes into view like a mirage, its pentagon shape and dead-straight edges giving away its man-made nature. The reservoir is one of hundreds built in the Pennines during the 19th century in order to supply textile mills. In its northeast corner however, is something entirely unique. Somehow, at 800 metres above sea level and 100 kilometres from the nearest coast, Gaddings Dam has a sandy beach.
In the summer, visitors trundle up the footpath with towels, buckets and spades to swim and sunbathe by the water. The sand is formed by weathering of the sandstone used to build the reservoir. The walls erode and prevailing winds blow waves and sediment into the northeast corner.
‘We are on the east side of the main fault line which runs northwest through Todmorden,’ says Paul Nicholson, chairman of the Gaddings Dam Group. ‘Our side consists of layers of millstone grit and shale.’ The millstone grit, a type of sandstone, was deposited around 315 million years ago when Britain was part of a larger continent close to the equator. This land mass would have had a warm climate and wide, shallow rivers, forming a tropical wetland. The water channels laid down sandy sediment, which later become the millstone grit. Meanwhile, the dead trees and plants became seams of coal and shale deposits. Millennia later, these resources would become essential to the industrial revolution that took place in this part of the country as the millstone was quarried for construction and the coal mined for fuel.
The embankments need constant maintenance. The pool’s location means this can be a challenge for the Gaddings Dam Group, which took ownership of the reservoir in 2001. ‘It’s not practical to bring machinery up here, so all our work is done by manual labour,’ says Nicholson. When millstone blocks fall into the water (around 3,000 so far), free divers have to fetch and haul them back into place. ‘We stopped bothering to count a few years ago,’ says Nicholson.
Aside from natural weathering, people pressure is also a concern. ‘News articles and social media have caused a steady increase in numbers,’ says Nicholson. ‘Fifteen years ago it would have been busy if 20 people were here, now we can count over 400 visitors on a summer day.’
This was published in the March 2019 edition of Geographical magazine
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