Darley Abbey Weir

A weir, constructed in c1782, situated in the River Derwent, to the immediate west of the former Boars Head Mills, listed at Grade I.

MATERIALS: coursed square gritstone blocks.

EXTERIOR: the weir, constructed in c1782, is situated in the River Derwent, to the immediate west of the former Boars Head Mills, listed at Grade I. The weir complex measures approximately 110m in length, and comprises a two-part weir structure constructed of coursed square gritstone blocks.

To the north is a concave sharp-crested weir curving upstream measuring approximately 20m in length, and a stepped spillway to the south measuring approximately 40m in length. To the south of the spillway is a coursed gritstone block wall running perpendicular to the spillway, containing two floodgates. The floodgates are joined to a natural island to the south (which is excluded from this assessment). The height of the weir is approximately 1.8m, and the floodgates have a depth of 1.2m.

To the south of the island is a sharp-crested weir and fish weir measuring approximately 25m in length. Above the weir is a C21 footbridge on metal supports. The north and south weirs are linked by a stone wall revetment running around the northern and western edges of the island topped by a C21 post and rail timber fence. On the north western edge of the island the modern fish weir cuts through the wall but the stone was retained, and on completion of the weir the stone work was reconstructed to match the original form.

The C21 footbridge following the line of the weir south of the island and the timber post and rail fence which sits above the revetment wall around the island are not considered to be of historic or architectural interest.

The weirs form part of a larger water management system associated with the late C18 Boars Head Mills at Darley Abbey, which also includes mill races from the River Derwent to the mill complex, sluice gates and tail races from the mill complex to the river. Only the weirs have been assessed for designation.

*Pursuant to s.1 (5A) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (‘the Act’) it is declared that the C21 fish pass and footbridge, the metal supports of the footbridge and the post and rail fence on the island revetment wall are not of special architectural or historic interest.