For centuries the river has been an important link to the sea for Bristol, and has long been navigable for sea going craft between Avonmouth and Bristol, and also for some shallow draft craft as far upstream as Hanham on the East side of the city. In the early 18th century, during the reign of William III a new course was cut to the south of the city extending for two miles diverting the river away from the city centre. The original course was utilized to provide better docks for the then increasing trade. Various acts were then passed during the reign of George III to improve the navigation for non-sea going craft between the docks in Bristol and the nearby affluent city of Bath. A series of six weirs and locks were created to make the river deep enough to enable barges to carry goods as far as Pulteney. A short distance downstream of Pulteney weir is the junction between the river Kennet and Avon Canal. The canal enabled goods to be taken inland to the various towns along its length and to London via the lower reaches of the Thames.
The poor state of Britain’s roads in the 18th century made the carriage of goods inland from busy ports like Bristol an expensive business. The navigable sections of rivers and the fast growing interlinking canal system were the solution to the problem. A cart pulled by a single horse could haul around a ton of goods; a single horse pulling a canal boat could haul about 30 tons. The merchants made good use of this significant cost saving, and there were rich pickings for the navigation companies which controlled the flow of traffic from the Bristol Channel on into the city of Bath and beyond. Small wonder that an act was passed proposing that the navigation be extended further up the Avon to allow neighboring towns such as Bradford on Avon to benefit. The navigation extension was never carried out though, perhaps the links that the Kennet and Avon, and Wilts and Berks canals provided were deemed to be enough, or perhaps the advent of rail travel and macadamized roads killed the proposal before it ever got underway. Either way the navigation extension work was never carried out which means that the uppermost point to which one can travel on a British waterways license is the famous horseshoe shaped Pulteney weir in the center of Bath.