The dam that isn't and the great floating plug of the Colden
Hebden Bridge History Society meeting report.
Speaker: Dave Smalley
Wednesday, 1 April 2015
Dave Smalley's investigation of Noah Dale dam starts with a story and an oddity in the landscape, as he explained to the Hebden Bridge Local History Society. The story is of a catastrophic collapse of the neglected dam at the head of Colden Water in the 1930s which carried the core of the dam downstream. The oddity in the landscape is the mound of earth which stands close to the breached dam wall and has been identified as the 'plug'. But big mounds of earth don't just float. Standing in the boggy ground at this remote spot, Dave was determined to find a more convincing explanation.
The dam itself was built between 1805 and 1810 so that water supply could be guaranteed to the spinning mills of the Colden Valley. Dave has established that the original dam was well built but it was shallow and could not hold enough water to supply all the mills. The owners took an enormous loan of £7000 in 1810 but in 1826 needed to invest in making the dam bigger. This raised the wall using rather shoddy engineering and was probably the cause of the dam's ultimate failure.
Examination of the landscape shows that the original dam had made use of existing landscape features, but had diverted the course of the Colden. The odd knoll is not a 'floating plug' but just part of a larger mound that was cut through by the navvies to keep the Colden flowing well.
A century later there were concerns about dam safety and new regulations demanded that the dam be kept in good repair. Those responsible were loath to spend more money on this, paying a waterman just £5 a year to inspect and maintain the structure. A report found a gap in the wall of the dam that had been raised, a fault that would cost £2000 to put right. The failed dam was left to decay further.
Stories have always suggested that the dam burst because of a serious rain storm - but the rainfall statistics don't support this theory. It seems that after a steadily wet year in 1938, the reservoir was beginning to hold water again, and the owners decided to dismantle it, probably by collapsing a tunnel. All the archaeology seems to support this surmise.
Dave's talk was a masterclass in showing how archaeology, geology, engineering, detective work in archives, analysis of photographs and simply tramping through bleak boggy moorland combine to add to our knowledge of the past and bring history to life. The result was a fascinating story about the construction of the Noah dale dam and its ultimate demise.
Hebden Bridge Local History Society season of talks starts again in September, but keep in touch with other events by looking at the website www.hebdenbridgehistory.org.uk
With thanks to Sheila Graham for this report
Previously, on the HebWeb
Gruelling Experiences - in the workhouse (16 March 2015)
Pre-History on our hill tops (9 March 2015)
Growing up in Sowerby (16 February 2015)
Patterns in the Landscape: the evolution of settlement and enclosure in the Upper Calder Valley (5 February 2015)
Wakefield Court Rolls for Family History: Sylvia Thomas (18 Jan 2015)
Happy Birthday Stoodley Pike: by Nick Wilding (16 Dec 2014)
Wills, Inventories and Economic Activity in the Parish of Halifax at the end of the 17th Century: Alan Petford (30 Nov 2014)
Local History Society Archive explored - Following the 65th AGM, members of Hebden Bridge Local History Society were treated to a sample of some of the treasures to be found in the Society's archive. (19 Nov 2014)
Views from two communities on the outbreak of war in 1914 - Mike Crawford, Wolfgang Hombach and Nick Wilding (27 Oct 2014)
The Listed Buildings of the Hebden Bridge area with Peter Thornborrow. (14 Oct 2014)
Valley of a Hundred Chapels by Amy Binns (29 Sept 2014)
History Group Study Day report: Power and Potability (11 Sept 2014)
Whose land is it anyway? How parliamentary enclosure shaped the landscape of the Calder Valley: speaker, Sheila Graham. Read more (6 April 2014)
Calder Valley Buildings of the Seventeenth Century: the craftsmen and their patrons Read more (27 Jan)See Small Ads (12 March)
Some thoughts on historic buildings and their repairs by Alan Gardner
More history reports in the HebWeb History Section