Throop Mill Sluice Gates

Throop Mill Sluice Gates

Sluice gates with flanking aprons and piers, dating to the 19th century with earlier origins. The gates and lifting mechanisms were replaced in the first half of the 20th century.

The structure is built of cut and coursed stone, comprising flanking aprons and five piers that define the hatches within the channel. The piers feature buttressed cutwaters on the lower (east) side and pointed cutwaters on the upper side. Six sluice gates are positioned within the hatches, each retaining two horizontal plates fixed to the flanking piers. Hand-operated lifting mechanisms, including wheeled ratchets and vertical shafts, survive intact. The superstructure demonstrates architectural quality in its masonry construction.

At the southern end is a concrete fish pass, erected in the late 20th century to prevent obstruction of fish by the sluice gates. A concrete and metal footbridge on the west side replaced an earlier timber footbridge.

The sluice gates were installed to regulate water flow to Throop Mill, acting as a bypass to divert excess water from the mill race into an overflow channel which rejoins the river to the northeast of Throop Mill. The ashlar abutments and piers forming the basic structure are shown on the first edition Ordnance Survey map of 1883 and have changed little since. The structure likely has earlier origins, as a mill is recorded in this parish in the Domesday Book, though its location is uncertain.

The sluice gates and their lifting mechanisms were replaced in the mid-20th century. The three forming the southern half were manufactured by the Dorset Iron Foundry Company in Poole; the northern three were made by Lott & Warne Ltd of Dorchester (1899–1956), iron founders and agricultural engineers. A stamp on each of the three northern gates indicates they were replaced by the Avon and Stour Catchment Board in 1936. Throop Mill underwent modernisation in the first half of the 20th century, with new equipment installed in phases between approximately 1926 and the late 1930s, during which time the sluice gates were also renewed. The mill ceased operating in 1974, and the sluice gates are no longer operational.

The sluice gates are a significant component of and integral part of the water control system for Throop Mill, forming a strong functional and visual group with the Grade II listed mill and contributing significantly to the character of the area.