Rennie's route passed to the north of Seend. To the west of the village, the Semington Brook flows northwards and then turns to the west, to join the Avon at Whaddon. The canal sweeps to the south to join the valley, and runs along its north bank to reach Semington. For the canal to head towards Trowbridge, a smaller bend was needed to cross the valley, with an aqueduct to carry it over the brook.Ordnance Survey, 1:25,000 map The contract for the construction of the aqueduct was won by James McIlquham and James Porteous. Both had worked together on the Leeds and Liverpool Canal and Porteus had been asked by Rennie to quote for the aqueduct over the River Lune on the Lancaster Canal, but had failed to secure the contract. The contract for the Semington aqueduct also included construction of the aqueduct at Avoncliff, to the west of Bradford-on-Avon, and both were completed successfully, as the two men went on to win the contract for the Dundas Aqueduct at Limpley Stoke.
