Robin Longbottom describes how a dam burst left a trail of destruction, but amazingly claimed no lives

TO the west of the Pennine Way, before it starts the climb over Ickornshaw Moor towards Ponden, there was once a large reservoir known as Cowloughton Dam.

At a glance there is nothing to suggest that it ever existed. However, on closer inspection the remains of the dam embankment and the overflow are discernible for those keen enough to explore the site.

It was built in the 1820s at the instigation of John Halstead of Colne, a cotton spinner who owned Ickornshaw Mill in the township of Cowling.

The four-storey mill had been built in 1791 by John Dehane, nephew of the Rev John Dehane – the vicar of Kildwick – who had died the previous year.

Dehane, who was himself a clergyman, had received a substantial legacy from his uncle and decided to invest it in the construction of a speculative mill at Ickornshaw.

When he was eventually appointed to the Parish of Beckbury in Shropshire he sold the mill, and by 1820 it was owned by John Halstead.

The mill was powered by a waterwheel fed from a small pond to the rear, but storing enough water to run the mill – especially in drought years – was a problem.

The year 1818 was a particularly bad one – springs ran dry, crops died in the fields and mills stood idle – and this may well have provided the impetus for Halstead to look for a solution.

The answer was to have a larger reservoir to keep his mill, and the others downstream, running in times of drought. And so Cowloughton Dam on Ickornshaw Moor was built.

He eventually passed the mill to his sons, Joseph and George. George left the partnership in 1838 and when Joseph was brutally murdered by a Colne mob in 1840, the mill was leased to William Watson.

It was under William Watson’s watch that things began to go wrong at the dam. A newspaper report in 1849 stated that “the embankment had for some time been in a condition to excite some anxiety with regard to its ultimate security”, but no action was taken.

Then towards 11 o’clock at night on Sunday, April 8, 1849, “the waters burst the embankment, and rushed with uncontrolled force and rapidity down the bed of the stream” towards the village of Ickornshaw.

It first hit Cowloughton Farm, which at that time was situated on the right bank of the beck. Fortunately, the bridge across the beck to the farm gave way and allowed the torrent of water to pass, which “enabled the occupiers of the house to rescue themselves and their cattle”.

As the water roared down Summer House Clough towards Ickornshaw it is said to have reached a height of 15 to 20 feet carrying with it huge stones, some weighing several tons.

The cottages on the beckside in Ickornshaw were in immediate danger.

The newspaper reported “the water entered a tenement occupied by a widow and her two small children, and immediately filled the room between 4 and 5 feet deep”. As there was no escape through the door, a hole had to be broken through the floor above and the battered mother and her children were pulled to safety.

Fortunately, no lives were lost but the damage was enormous.

Large trees were ripped out by the force of the water and “walls thrown down – rocks piled up against the stems of trees seven or eight feet in height”. In one place the ground had been washed away down to the bedrock, leaving a hole “big enough to contain a large house”.

The dam was never rebuilt, and the mill was by-passed by the torrent and survived undamaged.