Blunder Lock, spill weir and boundary markers

Blunder Lock, spill weir, and boundary markers are notable structures built in coursed limestone with ashlar dressings, while the wing walls have been rebuilt in brick. The lock features stone-built walls topped with large ashlar coping stones, and the gates at both ends of the chamber have limestone dressings. The timber gates were replaced in the late 20th century and are secured with iron fittings on the gateposts.

The spill weir, located on the north side of the lock along the towpath, is an essential part of the water management system for the canal, designed to maintain stable water levels. It consists of an open, roughly semi-circular, stone-lined trough for overflow. The south side of the basin has concrete-encased copings, and the overflow channel leading underground from the weir features two shallow, segmental-arched brick openings that rest on stone jambs and a central chamfered stone. Late 20th-century iron railings enclose the spill weir.

Additionally, the site includes two roughly-carved stone boundary markers located on the south side of the canal at either end of the lock pound, which likely date from the late 18th century.