The
River Avon () is a
river in the south west of
England. Because of a number of other Rivers Avon in England, this river is often also known as the
Lower Avon or
Bristol Avon. The name
Avon is a
cognate of the
Welsh word
afon meaning "river" (f is pronounced as v in Welsh).
The Avon
rises near
Chipping Sodbury in
Gloucestershire, dividing into two before merging again and flowing through
Wiltshire. In its lower reaches from
Bath to the
River Severn at
Avonmouth near
Bristol the river is navigable and known as the
Avon Navigation.
Etymology
The name
Avon is a
cognate of the
Welsh word
afon meaning "river" (f is pronounced as v in Welsh). "River Avon", therefore, literally means "River River". This explains why several English rivers have the name
Avon.
The
County of Avon that existed from 1974 to 1996 covering the Avon valley, including
Bristol and
Bath, was named after the river.
Course
The Avon
rises near
Chipping Sodbury in
Gloucestershire, between the villages of
Old Sodbury and
Acton Turville. Running a somewhat circular path, the river drains east and then south through
Wiltshire. Its first main settlement is the village of
Luckington, two miles (3 km) inside the
Wiltshire border, and then on to
Sherston. At
Malmesbury it joins up with its first major tributary, the
Tetbury Avon, which rises just north of
Tetbury in
Gloucestershire. This tributary is known locally as the Ingleburn, which in
Old English means 'English river'. Here, the two rivers almost meet but their path is blocked by a rocky outcrop of the
Cotswolds, almost creating an island for the ancient hilltop town of
Malmesbury to sit on.
After the two rivers merge, the Avon then turns south east away from the Cotswolds and then quickly south into the clay
Dauntsey Vale, where it is joined by the
River Marden, until it reaches the biggest town so far,
Chippenham. The wide vale is now known as the Avon Vale, and the river flows on via
Lacock to
Melksham, then turns north-west through
Bradford on Avon, where the centre of the town grew up around the
ford across the river Avon, hence the origin of the town's name ("Broad-Ford"). This was supplemented in
Norman times by the stone bridge that still stands today. The Norman side is upstream, and has pointed arches; the newer side has curved arches. The Town Bridge and Chapel is a grade I
listed building. It was originally a
Packhorse bridge, but widened in 17th century by rebuilding the western side. On the bridge stands a small building which was originally a
chapel but later used as a town lockup.
The Avon Valley between Bradford on Avon and Bath is a classic geographical example of a valley with all four forms of ground transport is found: road, rail, river, canal. The river passes under the
Avoncliff and
Dundas Aqueducts and at
Freshford is joined by the Somerset
River Frome. Avoncliff Aqueduct was built by
John Rennie and chief engineer
John Thomas, between 1797 and 1801. The
aqueduct consists of three arches and is 110 yards long with a central elliptical arch of 60 ft (18.3 m) span with two side arches each semicircular and 34 ft (10.4 m) across, all with V-jointed arch stones. The spandrel and wing walls are built in alternate courses of ashlar masonry, and rock-faced blocks. The central span sagged soon after it was built and has been repaired many times. The Dundas Aqueduct was built by the same team between 1797 and 1801 and completed in 1805.
James McIlquham was appointed contractor. The aqueduct is long with three arches built of
Bath Stone, with
Doric pilasters, and balustrades at each end. The central semicircular arch spans ; the two oval side arches span . It is a grade I
listed building, and was the first canal structure to be designated as an
Scheduled Ancient Monument in 1951. The stretch of river below and above the aqueduct, where it is joined by
Midford Brook, is used by the Bluefriars of the
Monkton Combe School Boat Club up to six days a week since at least the 1960s.
It then flows past
Claverton Pumping Station, which pumped water from the River Avon into the canal, using power from the flow of the river. The pumping station is located in a pump house built of Bath Stone, located at river level. Water is diverted from the river by Warleigh Weir, about 200 yd (180 m) upstream. The water flows down a
leat to the pumping station, where it powers a
water wheel, 24 ft (7.3 m) wide and 17 ft (5.2 m) in diameter, with 48 wooden slats. At full power the wheel uses 2
tons (2
tonnes) of water per second and rotates five times a minute. The water wheel drives gearing which increases the speed to 16
rpm. From here, cranks drive vertical connecting rods which transfer the energy to two 18 ft (5.5 m) long
cast iron rocking beams. Each rocking beam in turn drives an 18 in (0.5 m) diameter
lift pump, which also take their supply from the mill leat. Each pump stroke raises 50
imperial gallons (230
litres) of water to the canal. In 1981,
British Waterways installed two electric pumps just upstream from the station and presented the diesel pump to the Kennet and Avon Canal trust for preservation.
The Avon then flows through
Bathford, where it is joined by the
Bybrook River, and
Bathampton, joined by the
Lam Brook at Lambridge in
Bath and then it passes under
Cleveland and
Pulteney Bridges and over the weir. Cleveland Bridge was built in 1826 by
William Hazledine,Inscription on bridge owner of the
Coalbrookdale Ironworks, with
Henry Goodridge as the architect, on the site of a
Roman ferry crossing. Named after the 3rd
Duke of Cleveland, it spans the River Avon at
Bathwick, and enabled further development of
Georgian Bath to take place on the south side of the river. It was designed by architect
Henry Goodridge to take the traffic of his day, horse drawn vehicles and pedestrians, and was constructed using
Bath Stone and a
cast iron arched span. Pulteney Bridge was completed in 1773 and is designated by
English Heritage as a grade I
listed building. The bridge was designed by
Robert Adam, whose working drawings are preserved in the
Sir John Soane's Museum, and is one of only four bridges in the world with shops across the full span on both sides. It is named after
Frances Pulteney, heiress in 1767 of the Bathwick estate across the river from Bath. Pulteney approached the brothers Robert and
James Adam with his new town in mind, but Robert Adam then became involved in the design of the bridge. In his hands the simple construction envisaged by Pulteney became an elegant structure lined with shops. Adam had visited both
Florence and
Venice, where he would have seen the
Ponte Vecchio and the
Ponte di Rialto. But Adam's design more closely followed
Andrea Palladio's rejected design for the Rialto. Pulteney Bridge stood for less than 20 years in the form that Adam created. In 1792 alterations to enlarge the shops marred the elegance of the façades. Floods in 1799 and 1800 wrecked the north side of the bridge, which had been constructed with inadequate support. It was rebuilt by
John Pinch senior, surveyor to the Pulteney estate, in a less ambitious version of Adam's design. 19th-century shopkeepers altered windows, or cantilevered out over the river as the fancy took them. The western end pavilion on the south side was demolished in 1903 for road widening and its replacement was not an exact match. In 1936 the bridge became scheduled as a national monument, with plans being made for the restoration of the original façade. The restoration was completed in time for the
Festival of Britain in 1951, with further work being carried out in 1975. In 2009
Bath and North East Somerset council put forward plans to ban vehicles from the bridge and turn it into a pedestrianised zone.
The river is then joined by the
Kennet and Avon Canal which connects with the Avon just below the weir at
Bath Locks. Together with the
Kennet Navigation and the
River Thames it provides a through route for
canal boats from Bristol to
London. From this point downstream it is known as the Avon Navigation.
Navigation
The Avon then flows through
Keynsham towards
Bristol. For much of its course after leaving
Wiltshire, it marks the traditional boundary between
Somerset and
Gloucestershire. For most of this distance the navigation makes use of the natural river bed, with six locks overcoming a rise of . From Bath to
Netham Lock where it divides into the New Cut and the Floating Harbour is . The stretch is made navigable by the use of locks and weirs.
Weston Lock on the outskirts of Bath is in what now forms the
Newbridge. Weston cut is a man made channel, opened in 1727, for boats to approach and pass through Weston lock, which 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 river side in the early 18th century.
Kelston Lock and
weir have permanent moorings above and below them. The Riverside Inn and Saltford Marina are also close by.
Saltford Lock and weir are overlooked by the remains of the
Kelston Brass Mill, which was working until 1925. It is a grade II
listed building. Alongside the lock is a
pub, whose garden extends over the lock to the small island between the lock and weir. The lock was opened in 1727 and destroyed in 1738 by rival coal dealers to stop the use of the river for transportation. In its heyday, between 1709 and 1859
Swineford had an active
brass and
copper industry around the
Swineford Lock which were served by the river which also provided water power for the cloth industry, as did the
River Boyd, a tributary which flows into the Avon near
Bitton.
Keynsham Lock opened in 1727. Just above the lock are some visitor moorings and a
pub, on an island between the lock and the
weir. The weir side of the island is also the mouth of the
River Chew.
Hanham is the last tidal lock, after which the river is joined by
Brislington Brook.
Netham lock is the point at
Netham in
Bristol at which boats from the
River Avon, gain access to Bristol's
Floating Harbour. Construction started in 1804 to build the tidal
New Cut, where it is joined by the
River Malago, and divert the
River Avon along the Feeder Canal to the harbour; a system designed and built by
William Jessop and later improved by
Isambard Kingdom Brunel. A
weir carries the river into the New Cut and boats use the adjacent
lock. Access to the harbour is only possible during the day when the lock keeper will open the gates unless the water level in the river between Netham and Hanham is above or below the level of the harbour. Netham Lock and the weir form part of Bristol's flood defence mechanisms and it was announced in December 2008 that they would be upgraded as part of the £11 million City Docks Capital Project.
In central Bristol, where the river is
tidal, it is diverted from its original course onto the
New Cut, a channel dug between 1804 and 1809 at a cost of
£600,000. The original course is held at a constant level by
lock gates (designed by
Jessop) and is known as the
Floating Harbour. The Floating Harbour is protected by a 1870s replacement for Jessop's
locks. This unusual dock has a tentacled plan resulting from its origins as the natural river course of the Avon and its
tributarys, the
River Frome and
Siston Brook, and is intimately entwined with Bristol's city centre as few docks are. As a result of this, the Floating Harbour is one of the more successful pieces of dockland regeneration, with much of the dockside now occupied by residential, office and cultural premises, and the water area heavily used by leisure craft. The Floating Harbour gave the port an advantage by enabling shipping to stay afloat rather than grounding when the tide went down. Downstream of central Bristol the river passes through the deep
Avon Gorge, spanned by Brunel's
Clifton Suspension Bridge, the river is
tidal and is navigable by sea going vessels at
high tide but drying to a steep sided muddy channel at
low tide. It was largely the challenge of navigating this section that sealed the fate of the Floating Harbour as commercial docks, and saw them replaced by docks at
Avonmouth where the Avon joins the
Severn estuary.
Before reaching its mouth it is joined by the
River Trym at
Sea Mills which was the site of
Portus Abonae a
Roman port, and passes under the
Avonmouth Bridge which carries the
M5 motorway. The main span is long, and the bridge is long, with an air draught above mean high water level of . The river then serves two major dock areas. The
Royal Portbury Dock on the southern side of the mouth of the river. The deepwater dock was constructed between 1972 and 1977, and is now a major port for the import of
motor vehicles. The Royal Portbury Dock has the largest entrance lock into any UK port, accommodating vessels up to beam, length and draft. The
Avonmouth Docks are on the north side of the river and are one of the UK's major ports for chilled foods, especially fruit and vegetables. The first dock at Avonmouth, Avonmouth Old Dock, was opened in 1877. It was acquired by the Bristol Corporation in 1884. In 1908, a much larger dock, the Royal Edward Dock, was opened. The docks form part of the
Port of Bristol and were operated by the Port of Bristol Authority, part of
Bristol City Council, until 1991, when the council granted a 150 year lease to the Bristol Port Company.
Biodiversity
The river is important for its dragonfly communities, with a strong population of
Scarce Chaser (found in only six other areas in England), together with a strong population of
White-legged Damselfly.
Red-eyed Damselfly is also found.
The river is also important for aquatic plants, including
Loddon Pondweed.
The
Avon Gorge has been designated as a
Site of Special Scientific Interest because it supports some rare fauna and flora, including species unique to the gorge. There are a total of 24 rare plant species and two unique trees: the
Bristol and
Wilmotts's whitebeams.BBC Bristol, "
The Avon Gorge - Bristol's Great Glacier?" Accessed 2006-05-05. Other notable plants include
Bristol Rock-cress,
Bristol onion,Avon Wildlife Trust, "
The wildlife and habitats of Avon." Accessed 2009-03-24.
Spiked Speedwell,
Autumn Squill and
Honewort.Myles (2000), page 161 . Other areas along the river which have this designation include
Bickley Wood,
Cleeve Wood, Hanham for its large population of Bath Asparagus (
Ornithogalum pyrenaicum).
Stidham Farm near
Keynsham contains at least At least of
Pleistocene terrace-gravels, consisting of
limestone clasts mainly, but also with
Millstone Grit, Pennant
Sandstone, flint and chert clasts. The site is of considerable importance for studies relating to the possible glaciation of the area, and of the terrace
stratigraphy, particularly as it is one of only two accessible terrace deposits in this part of the Avon valley.
English Nature citation sheet for the site (accessed 13 July 2006)
Newton Saint Loe is also listed for geological reasons as it represents the only remaining known exposure of fossiliferous
Pleistocene gravels along the River Avon. In conjunction with other sites within the wider area, they have aided the development of a scientific understanding of the history of early
glaciation within
South West England.
At
Horseshoe Bend, Shirehampton the wooded cliff and a narrow
salt marsh are supported by rocks of
Devonian sandstone and
Carboniferous limestone, overlain by with
Triassic Dolomitic conglomerate. The site's principal interest and the reason for its designation as an SSSI is the presence of a population of the
True Service-tree (
Sorbus domestica) growing on the cliffs. This tree is nationally rare in Britain, and this site hosts the largest known population in England. Other notable species of
Sorbus here are the whitebeams
Sorbus eminens and
Sorbus anglica, both of which are also nationally rare in Britain. The nationally scarce
Large-leaved Lime (
Tilia platyphyllos) also occurs, and herbs include
Field Garlic (
Allium oleraceum) and
Pale St. John's-wort (
Hypericum montanum). The saltmarsh vegetation, which lies at the base of the cliff, is predominantly made up of
Sea Aster (
Aster tripolium) and
English Scurvygrass (
Cochlearia anglica). There are however two nationally scarce vascular plant species here as well -
Slender Hare's-ear (
Bupleurum tenuissimum) and
Long-stalked Orache (
Atriplex longipes).
The tidal reaches of the River Avon provide habitat for waterbirds, with 64 species having been recorded up to 2004,Rogers, M. A. (2004) Waterbirds of the Tidal Avon at Sea Mills Reach
Bristol Ornithology 27: 45-52 including 21 species of
shorebird,Rogers, M. A. (2002) Waders of the Tidal Avon at Sea Mills Reach
Bristol Ornithology 26: 3-22 and 13 species of
gull.Rogers, M. A. (2002) Gulls of the Tidal Avon
Bristol Ornithology 26: 23-36
History
The river Avon had been navigable from Bristol to Bath during the early years of the 13th century but construction of mills on the river forced its closure.
The
Bristol Avon Navigation was constructed between 1724 and 1727, following legislation passed by
Queen Anne, by a company of proprietors and the engineer
John Hore of
Newbury. The first cargo of 'Deal boards, Pig-Lead and Meal' arrived in Bath in December 1727. It is now administered by
British Waterways.
Route and points of interest
References
See also
External links