[citation needed] At its full capacity the reservoir covers an area of 70.8 ha (175 acres) and at its deepest point is 34.7 m (114 ft) deep.

[2] Construction of the neo-Gothic solid masonry dam began in 1902, a year after the building of Howden commenced, and proved a mammoth task.

The huge stones that formed the walls of the dam were carried along a specially created railway from the quarries at Bole Hill near Grindleford.

[citation needed] The filling of the reservoir began in November 1914, and overflowed for the first time in January 1916, with the water almost immediately passing into supply.

[citation needed] Between 1901 and 1903 a standard-gauge railway of over 7 mi (11 km) was built from the village of Bamford to the south of the reservoir to Howden, to carry the thousands of tons of stone required for the construction of the two dams.

[citation needed] After supplying well over a million tons of stone the Bole Hill quarry was closed in September 1914, with the end of the railway following soon after.

The exhibition now closed, was owned and run by the late Vic Hallam, and covered stories of 617 Squadron and its training for Operation Chastise.

In September 2014, a unique flypast took place with the two remaining airworthy Lancasters, one from the Battle of Britain Memorial Flight, and one from Canada, flying three passes in formation.