The original Dale Dyke dam situated 9 miles west of Sheffield on the River Loxley, a tributary of the River Don, collapsed suddenly on the 11th March, 1864. Nearly 250 people lost their lives and there was considerable damage to property, including some in the city itself.Amey (1974) gives a very readable account of the disaster and its aftermath.
Expert opinion at the time was divided as to the cause of the collapse of the dam, sometimes referred to by contemporary writers as the Bradfield dam from its location near the village of Bradfield in Bradfield Dale. One school of thought maintained that it was due to leakage from pipes beneath the embankment and consequential erosion, and another that it was due to a landslide which encroached upon the downstream toe of the embankment. More than 100 years have passed since these and other theories on the cause of the breach were put forward. In the light of the experience that has been gained since then in the behaviour of earth dams, an attempt has been made to draw fresh conclusions from a review of the evidence.
An inquest on the disaster was held on 24th and 25th March 1864; a verbatim account is given in a contemporary Parliamentary report (Sheffield Waterworks Bill 1864). Both the Sheffield Waterworks Company, who owned the reservoir, and the Sheffield Corporation, who wished to buy out the waterworks company, engaged consulting engineers to investigate the failure and their reports are available