Bilberry Reservoir
The Bilberry Reservoir (south west of Holmfirth), Boshaw Whams and Holme Styes were constructed by the Holme Reservoir Commissioners to store water for use by textile mills in the Holme Valley.
The embankment of the Bilberry Reservoir had been built on top of a small spring which gradually eroded the puddle clay core, leading to the central section of the embankment slumping down below the level of the reservoir's waste pipe. Following a prolonged period of heavy rain, the reservoir began overflowing at around midnight on 5 February 1852. Shortly afterwards the entire central section of the embankment collapsed and millions of gallons of water poured down the Holme valley in a devastating flood that killed about 80 people.[1]
The inquest jury found 'that the reservoir was defective in its original construction, and that the Commissioners, engineer and overlooker, were culpable in not seeing to the proper regulation of the works, and that the Commissioners, in permitting the Bilberry reservoir to remain for several years in a dangerous state, with the full knowledge thereof, and not lowering the waste pit, have been guilty of gross and culpable negligence ....'[2]
See here for an excellent account of the events associated with the collapse of Bilberry Dam [3]