The River Avon was navigable from Bristol to Bath during the early years of the 13th century, until the construction of mills on the river forced its closure.

The modern Avon is navigable from its mouth at Avonmouth, through the Floating Harbour in Bristol, as far as Pulteney Weir in the centre of Bath and just beyond the start of the canal.
Beyond Pulteney Weir the Avon is still navigable as far as the weir and site of the old "flash lock" at Bathampton but the lock at Pulteney has been replaced only with a small boat slide for dinghies and canoes.
The stretch from Bristol to Bath is made navigable by the use of locks and weirs at Hanham, Keynsham, Swineford, Saltford, Kelston and Weston, which together overcome a rise of 30 feet (9 m) within 12 miles (19 km).

Lock number one on the Kennet and Avon Canal is Hanham Lock, first opened  as part of the Avon Navigation in 1727.
It is the first lock east of Netham, the upstream limit of the Floating Harbour, beyond the suburbs of the city of Bristol.
A colliery wharf was sited just west of the lock, but the nearby coal mines closed in the 19th century.
The river below Hanham Lock is considered to be tidal, as high tides often pass over the weir at Netham.
Some spring tides pass over the weir at Hanham, making the river tidal up to Keynsham Lock.
Heading east, the river passes the Somerdale Factory, on its southern bank, which was a chocolate production factory for Cadbury – originally built by the Fry family in the 1920s and 1930s.
On the northern bank is Cleeve Wood, the primary scientific importance of which lies in its particularly large population of Bath asparagus (Ornithogalum pyrenaicum).

A public house has been built on the island between Keynsham Lock and the weir.
The weir side of the island is also the mouth of the River Chew.

The river then passes through Avon Valley Country Park and past Stidham Farm, another SSSI that contains Pleistocene terrace-gravels of the river.
A depth of at least 7 feet (2 m) of sandy gravels are recorded, consisting mainly of limestone clasts, but also with Millstone Grit, Pennant Sandstone, flint, and chert clasts.
The river passes under the old railway line that now forms the Avon Valley Railway, a three-mile-long (5 km) heritage railway, before reaching Swineford Lock.
Here, between 1709 and 1859, there was an active brass and copper industry served by the river, which also provided water power for the cloth industry.
The remains of Kelston Brass Mill, which was working until 1925, are next to Saltford Lock.
The lock was opened in 1727 but destroyed by rival coal dealers in 1738, to prevent the river being used for transportation.

The Bristol and Bath Railway Path crosses the navigation several times before reaching the suburb of Newbridge on the outskirts of Bath.
Here the A4 crosses close to the Newton St Loe SSSI, which is designated an SSSI because it represents the only remaining known exposure of fossiliferous Pleistocene gravels containing the remains of mammoths (Mammuthus) and horses (Equus) along the river, and has aided the development of a scientific understanding of the history of early glaciation in South West England.
The final lock before entering Bath is Weston Lock, opened in 1727.
Its construction created an island between the cut and the river weir, which became known as Dutch Island after the owner of the brass mill established on the riverside in the early 18th century.
The River Avon was navigable from Bristol to Bath during the early years of the 13th century, until the construction of mills on the river forced its closure.
The modern Avon is navigable from its mouth at Avonmouth, through the Floating Harbour in Bristol, as far as Pulteney Weir in the centre of Bath and just beyond the start of the canal. Beyond Pulteney Weir the Avon is still navigable as far as the weir and site of the old "flash lock" at Bathampton but the lock at Pulteney has been replaced only with a small boat slide for dinghies and canoes. The stretch from Bristol to Bath is made navigable by the use of locks and weirs at Hanham, Keynsham, Swineford, Saltford, Kelston and Weston, which together overcome a rise of 30 feet (9 m) within 12 miles (19 km).
Lock number one on the Kennet and Avon Canal is Hanham Lock, first opened  as part of the Avon Navigation in 1727. It is the first lock east of Netham, the upstream limit of the Floating Harbour, beyond the suburbs of the city of Bristol. A colliery wharf was sited just west of the lock, but the nearby coal mines closed in the 19th century. The river below Hanham Lock is considered to be tidal, as high tides often pass over the weir at Netham. Some spring tides pass over the weir at Hanham, making the river tidal up to Keynsham Lock. Heading east, the river passes the Somerdale Factory, on its southern bank, which was a chocolate production factory for Cadbury – originally built by the Fry family in the 1920s and 1930s. On the northern bank is Cleeve Wood, the primary scientific importance of which lies in its particularly large population of Bath asparagus (Ornithogalum pyrenaicum).
A public house has been built on the island between Keynsham Lock and the weir. The weir side of the island is also the mouth of the River Chew.
The river then passes through Avon Valley Country Park and past Stidham Farm, another SSSI that contains Pleistocene terrace-gravels of the river. A depth of at least 7 feet (2 m) of sandy gravels are recorded, consisting mainly of limestone clasts, but also with Millstone Grit, Pennant Sandstone, flint, and chert clasts. The river passes under the old railway line that now forms the Avon Valley Railway, a three-mile-long (5 km) heritage railway, before reaching Swineford Lock. Here, between 1709 and 1859, there was an active brass and copper industry served by the river, which also provided water power for the cloth industry. The remains of Kelston Brass Mill, which was working until 1925, are next to Saltford Lock. The lock was opened in 1727 but destroyed by rival coal dealers in 1738, to prevent the river being used for transportation.
The Bristol and Bath Railway Path crosses the navigation several times before reaching the suburb of Newbridge on the outskirts of Bath. Here the A4 crosses close to the Newton St Loe SSSI, which is designated an SSSI because it represents the only remaining known exposure of fossiliferous Pleistocene gravels containing the remains of mammoths (Mammuthus) and horses (Equus) along the river, and has aided the development of a scientific understanding of the history of early glaciation in South West England. The final lock before entering Bath is Weston Lock, opened in 1727. Its construction created an island between the cut and the river weir, which became known as Dutch Island after the owner of the brass mill established on the riverside in the early 18th century.
Kennet and Avon Canal