Lea Bridge Lock remained in operation until 1853, when it was demolished. It was replaced by Pond Lane Lock, which was built in 1865 at Cow Bridge, about halfway between Lea Bridge and Homerton Lock. Seven years later, the navigation was rebuilt so that it was level from Tottenham to Old Ford, and the lock was then redundant, but was retained to help protect the navigation below it in times of flood. It was removed in 1931, when it was superseded by a new structure with vertical guillotine gates, located a little further upstream. These became redundant with the construction of the Thames Barrier, and the gates were removed in 1987. Homerton lock was removed in the 1860s, following dredging of the river down to Old Ford. Old Ford Lock was rebuilt as a pair of locks on a different alignment in 1856, and the junction with the old course of the River Lee was reworked to remove an awkward bend. They were known as the small lock and the large lock, one being wide and the other being wide. Both were rebuilt with a width of in 1935, but retained their names, the small lock being shallower than the large lock. Further rebuilding had to take place during the Second World War after they were hit by a bomb on 19 October 1940, which also destroyed the lock houses. New lock houses were built in 1946, and were sold in the 1990s, after which they were used as the location for the television programme "The Big Breakfast". From 1829, water was abstracted at Lea Bridge, from the natural watercourse, by the East London Waterworks Company, to avoid the increasing pollution of the Navigation. The waterworks was located to the south of Old Ford Locks, and the company built a canal in 1830 which ran along the east bank of the Hackney Cut to transfer water from Lea Bridge for processing. William Hoof, who had gained a reputation as a specialist tunnelling contractor, after working on Strood Tunnel for the Thames and Medway Canal and Harecastle Tunnel on the Trent and Mersey Canal, worked on the waterworks project from 1829 until 1834. In 1824, George Duckett, the son of Sir George Duckett, 1st Baronet who had owned the Stort Navigation, obtained an Act of Parliament to link the Hackney Cut to the Regents Canal, which he hoped would result in much of the trade which passed onto the Thames from the Lee Navigation being re-routed to Regents Canal Dock. The Hertford Union Canal, which was long, included three locks, and joined the cut a short distance above Old Ford Locks, opened in 1830 but failed to attract much traffic, due to the level of tolls.