 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.