Here, Robin Longbottom examines the history of a reservoir whose original purpose was very different from the role it fulfils today

ONE of the most popular walks in the Keighley area is from Slippery Ford to Keighley Reservoir – and beyond across the moors for the more adventurous.

Now owned by Yorkshire Water, most walkers will assume that the reservoir had been built to provide drinking water for the people of Keighley.

However, they would be quite wrong, as it was originally a reserve of water to power the mills downstream to Keighley and it is still known locally as the Big Dam.

In 1826, and for a number of years afterwards, the country suffered from a series of droughts which brought many of the water-powered mills in the area to a standstill.

Therefore, the mill owners and tenants along the North Beck in Keighley, together with those upstream along Laycock Beck and those lower down on the River Worth, looked for a solution to the problem.

Along the course of both becks and the river there were a total of 14 mills – 11 worsted and cotton spinning mills, one paper mill, one machine-making works and one corn mill – all of which, to a greater or lesser extent, relied upon water to power their machinery.

Apart from the mill owners and tenants, there was one other important person who had a vested interest in mills along the beck – William Cavendish the 2nd Earl of Burlington, who later became the 7th Duke of Devonshire.

Five of the mills – Castle Mill, North Beck Mill, Becks Mill, Keighley Corn Mill and Low Mill – together with their dams and goits, were built on his land and for which he received the rents. William Cavendish also owned Keighley Moor.

In about 1832 all the parties met and concluded that the answer would be to build a large mill dam on Keighley Moor to ensure that their mills would have a continuous source of power in the event of further droughts.

The construction took eight years and the parties contributed to the cost according to the amount of water needed to power their water wheels.

William Cavendish paid the largest contribution and would recoup this cost through annual charges made to the mills.

In 1856 Cavendish was receiving £120 - 7 shillings per annum in rent from the 14 mills. John Brigg, of Brow End Mill at Goose Eye, now converted into houses and known as the Rag Mill, paid the most rent, a total of £15 - 18 shillings - 3 pence, whilst George Hattersley paid only £1 - 19 shillings - 9 pence to power a small water wheel in his machine works at North Brook Mill, in Keighley.

For almost a hundred years many of the mills relied on the becks and the river for the water needed to run their water wheels and steam engines.

However, after the end of the First World War, the power source quickly changed over to electricity. This new power source had been heralded by the new Becks Mill built in 1908 and reputed to have been the first mill in Keighley to be run solely on electric power.

In 1939, the 10th Duke of Devonshire sold the Big Dam to Keighley Corporation for £1 but it was not until 1954 that they constructed the present road to get access to it.

When it subsequently passed to the Craven Water Board in 1959 they drained and cleaned it out and built a conduit across the moor to the water treatment plant at Oldfield.

Today the reservoir, now owned by Yorkshire Water, provides Keighley and district with a large part of its drinking water.