 Old Ford Lock marks the start of the Hackney Cut – an artificial channel built in the 18th century to cut off a large loop in the natural channel.The natural river rejoins the Navigation at this point – below the lock, having travelled from the Middlesex Filter Beds Weir, just below Lea Bridge; and passing to the east of the Navigation.The Old River Lea (the natural channel), is joined by the River Lee Flood Relief Channel, and Dagenham Brook before connecting to the Bow Back Rivers, which join the tidal Bow Creek.