Lledan Brook Aqueduct and Weir

History: The Montgomeryshire Canal was constructed between 1794 and 1797, but the original aqueduct at this site was replaced in 1836 by J.A.S. Sword, who was the canal company's engineer from 1833. Its design was modelled on the earlier aqueduct by George Buck at Brithdir, which had been built in 1819.

Description: Base and sides of aqueduct formed from a series of bolted cast-iron plates, flanked by paths carried on brick arches. These have conventional segmental arches with rusticated stone voussoirs, with an inscribed tablet above the western arch recording 'J. Sword, Engineer, 1836'. The tow-path side is surmounted by cast-iron railings with trellised decoration, between panelled ashlar terminal piers with domed caps.

On the western side of the aqueduct, brick retaining walls to either bank of the brook flank the pool below a circular weir. This was probably rebuilt with the aqueduct in 1836, and existed to divert water to Domen cornmill.

The aqueduct is a fine example of the engineering associated with the Montgomeryshire Canal, of considerable interest for its engineering as well as for its architectural character. Together with the weir, it forms an important component in a group of structures at the major canal wharf at Welshpool.

Reference: Stephen Hughes, The Archaeology of the Montgomeryshire Canal, 1988, pp.25, 28-9.