River Thaw
Encyclopedia
The River Thaw is a river
in the Vale of Glamorgan
, south Wales
. At 20 kilometres/12.4 miles, it is the longest river entirely in the Vale of Glamorgan.
near Llanharry
. It flows in a generally south-eastern direction through the town of Cowbridge
, then turns southward and reaches the Bristol Channel
at Breaksea Point
, south of Aberthaw
.
. However, several stretches of the river suffered degradation by the over-grazing of cattle, and the river no longer supports a single European water vole, despite having a once sizeable population. Unlike many rivers in south Wales, the Thaw was never subject to much pollution, except at its mouth which was diverted to feed the Aberthaw Power Station
. In the last century, there has been a slight decline in the river's biodiversity, but it is still very much favoured by anglers. Its major tributary, the Kenson River, is actually rather polluted in its lower reaches due to agricultural runoff and effluents leaking from nearby quarries
.
The river is also a popular site for various kinds of recreation, accessible for much of its course, much of which is used for agriculture. There are many archaeological sites along the river, too, because it was once large enough for the villages and settlements along its banks to have access to shipping and thus the sea. Its flow was comparable to those of other Welsh rivers, but, like them, the Thaw silted up. The effects of this were so bad that its once potent size was drastically reduced, appearing now as little more than a large stream.
The river picks up many tributaries along its course, making its watershed the largest in the Vale.
The Kenson River is by far the largest tributary of the river. It has a total length of 2 miles and is formed at the confluence of two ther rivers, the Waycock and the Nant Llancarfan. It runs southwest through the village of Penmark
and near Rhoose
and Cardiff International Airport
. The Kenson is also known for its good angling, and had many tributaries of its own. These include the River Waycock which is itself 9 kilometres long, and flows through Dyffryn
and Penmark
. It has many sources between Wenvoe
and St Lythans
, and meets the Nant Llancarfan at Penmark. The Nant Llancarfan rises at Bonvilston
, flowing southward for 5 miles.
A stream known as the Factory Brook is a mile and a half long. It flows east, to meet the Thaw at Cowbridge.
The Nant y Stepsau is 2 miles long. Rising between the villages of Llanmaes and Eglwys Brewis, it flows northeast.
The Nant Tre-gof is a minor tributary of the river. It starts near the small village of Llantrithyd near the A48
and flows southwest for nearly 3 miles, through the hamlet of Treguff (this name is a corruption of Tre-gof). Its confluence with the Thaw is nearly opposite that of the Nant y Stepsau.
The Nant Aberthin is the smallest named tributary. It flows through the small village of Aberthin
, and is under a mile long. Its actual name is Nant y Berthyn - Aberthin is a corruption of this name.
An unnamed brook flows through St Athan
. Its length is approximately 1.5 miles, and it joins the Thaw near its mouth.
The Nant Llanmihangel is over a mile long. It comes from Llanmihangel, and flows into the river at Llandough
, south of Llanblethian.
There are many insignificant, and thus unnamed, tributaries of the Thaw. One flows in the same direction of the Thaw for a mile or so, and flows amongst a dismantled railway and power cables. The stream in question meets the Thaw near the village of Flemingston and is very near the aforementioned Nant Tre-gof.
at a shingle beach called Leys Beach, at Breaksea Point
, one of the southernmost points of Wales. It flows through the village of Aberthaw
. At its mouth is the Aberthaw Power Station, which is split into two complexes, Aberthaw A and Aberthaw B, on the opposite sides of the river. When Aberthaw A first opened in February 1966, it was the most advanced power station in the world. Aberthaw B opened in the 1970s. The power station currently burns coal with a generating capacity 1455 megawatts, and proposals for a nuclear power station on the site were rejected due to close proximity to Cardiff
. Aberthaw A was subsequently demolished in 1995.
For centuries, an active, albeit small, port stood at the river's mouth, and provided docking facilities. In those days, the river was large and navigable by ships for some considerable distance; however, the river began silting up some time in the late 18th century. Its flow and size were so badly degraded that shipping was restricted to a few small vessels, but by 1850 it was of no use at all to shipping as it had become no more than a large stream. The port was abandoned altogether by 1900.
The Thaw was used to cool the power station, which led to a small amount of thermal pollution in the river's mouth. The estuary is not natural, because the river was diverted into a channel to allow the power station to be built, similar to the Cadoxton River
a few miles east. The river's original mouth was actually slightly further east of here; many lagoons, small pools and saltmarshes are left over from its once large estuary.
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
in the Vale of Glamorgan
Vale of Glamorgan
The Vale of Glamorgan is a county borough in Wales; an exceptionally rich agricultural area, it lies in the southern part of Glamorgan, South Wales...
, south Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
. At 20 kilometres/12.4 miles, it is the longest river entirely in the Vale of Glamorgan.
Course
Its source is in the hills just south of the M4 MotorwayM4 motorway
The M4 motorway links London with South Wales. It is part of the unsigned European route E30. Other major places directly accessible from M4 junctions are Reading, Swindon, Bristol, Newport, Cardiff and Swansea...
near Llanharry
Llanharry
Llanharry is a small village in the county borough of Rhondda Cynon Taf, Wales.Historically Llanharry has been inextricably linked with iron mining as far back as the Roman period and Elizabethan era, and for a period in the 20th century it boasted the only iron mine in Wales.-Employment:Llanharry...
. It flows in a generally south-eastern direction through the town of Cowbridge
Cowbridge
Cowbridge is a market town in the Vale of Glamorgan in Wales, approximately west of Cardiff. Cowbridge is twinned with Clisson in the Loire-Atlantique department in northwestern France.-Roman times:...
, then turns southward and reaches the Bristol Channel
Bristol Channel
The Bristol Channel is a major inlet in the island of Great Britain, separating South Wales from Devon and Somerset in South West England. It extends from the lower estuary of the River Severn to the North Atlantic Ocean...
at Breaksea Point
Breaksea Point
Breaksea Point is the southernmost point of mainland Wales .- Location :Breaksea Point is located in the Vale of Glamorgan and is part of the Heritage Coast of South Wales....
, south of Aberthaw
Aberthaw
Aberthaw is a village of the Vale of Glamorgan west of Barry on the coast of South Wales.The village is split into two halves - East Aberthaw and West Aberthaw, separated by the River Thaw. It is home to Aberthaw Cement Works and Aberthaw Power Station a coal power station plant that was linked to...
.
Environment
The river is renowned for its plenitude and variety of fishFish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
. However, several stretches of the river suffered degradation by the over-grazing of cattle, and the river no longer supports a single European water vole, despite having a once sizeable population. Unlike many rivers in south Wales, the Thaw was never subject to much pollution, except at its mouth which was diverted to feed the Aberthaw Power Station
Aberthaw Power Station
Aberthaw Power Station refers to a series of two coal-fired power stations situated on the coast of South Wales, near Barry in the Vale of Glamorgan. It is actually located on the waterfront of the nearby villages of Gileston and West Aberthaw on Limpert Bay...
. In the last century, there has been a slight decline in the river's biodiversity, but it is still very much favoured by anglers. Its major tributary, the Kenson River, is actually rather polluted in its lower reaches due to agricultural runoff and effluents leaking from nearby quarries
Quarries
Quarries - The "Royal Quarries" — not found in Scripture — is the namegiven to the vast caverns stretching far underneath the northern hill, Bezetha, on which Jerusalem is built. Out of these mammoth caverns stones, a hard limestone, have been quarried in ancient times for the buildings in the...
.
The river is also a popular site for various kinds of recreation, accessible for much of its course, much of which is used for agriculture. There are many archaeological sites along the river, too, because it was once large enough for the villages and settlements along its banks to have access to shipping and thus the sea. Its flow was comparable to those of other Welsh rivers, but, like them, the Thaw silted up. The effects of this were so bad that its once potent size was drastically reduced, appearing now as little more than a large stream.
Tributaries
The river picks up many tributaries along its course, making its watershed the largest in the Vale.
The Kenson River is by far the largest tributary of the river. It has a total length of 2 miles and is formed at the confluence of two ther rivers, the Waycock and the Nant Llancarfan. It runs southwest through the village of Penmark
Penmark
Penmark is a rural village south-west of Barry near Rhoose in the Vale of Glamorgan, in South Wales. The village is a parish and is of a distinct narrow shape. It has a parish church along the main road running through the village. It is also home to the Penmark United Under 15's football team...
and near Rhoose
Rhoose
Rhoose is a village and community located near the sea in the Vale of Glamorgan, Wales, near Barry.The village is the location of Cardiff International Airport, formerly RAF Rhoose, a Holiday Park , some shops, two public houses , Rhoose Social Club, and an active Surf Life Saving Club Rhoose is...
and Cardiff International Airport
Cardiff International Airport
Cardiff Airport is an international airport serving Cardiff, and the rest of South, Mid and West Wales. Around 1.4 million passengers passed through the airport in 2010....
. The Kenson is also known for its good angling, and had many tributaries of its own. These include the River Waycock which is itself 9 kilometres long, and flows through Dyffryn
Dyffryn
Dyffryn may refer to one of these places in Wales:*Dyffryn, Bridgend*Dyffryn Cennen, Carmarthenshire*Dyffryn, Ceredigion*Dyffryn, Neath Port Talbot *Dyffryn, Pembrokeshire*Dyffryn Gardens...
and Penmark
Penmark
Penmark is a rural village south-west of Barry near Rhoose in the Vale of Glamorgan, in South Wales. The village is a parish and is of a distinct narrow shape. It has a parish church along the main road running through the village. It is also home to the Penmark United Under 15's football team...
. It has many sources between Wenvoe
Wenvoe
Wenvoe is a Welsh village between Barry and Cardiff in the Vale of Glamorgan, Wales. Nearby is the Wenvoe Transmitter near Twyn-yr-Odyn and the HTV Wales Television Centre at Culverhouse Cross in the suburbs of Cardiff.-History:...
and St Lythans
St Lythans
St Lythans is an affluent hamlet and former parish in the Vale of Glamorgan, southeast Wales, just outside of western Cardiff. It lies southwest of Culverhouse Cross, west of Wenvoe and southwest of Twyn-yr-Odyn and is also connected by road from Dyffryn and the Five Mile Lane in the west...
, and meets the Nant Llancarfan at Penmark. The Nant Llancarfan rises at Bonvilston
Bonvilston
Bonvilston is a village in the Vale of Glamorgan, Wales. The village is situated on the A48 about four miles east of Cowbridge and near the Welsh capital city of Cardiff.- History & Amenities :...
, flowing southward for 5 miles.
A stream known as the Factory Brook is a mile and a half long. It flows east, to meet the Thaw at Cowbridge.
The Nant y Stepsau is 2 miles long. Rising between the villages of Llanmaes and Eglwys Brewis, it flows northeast.
The Nant Tre-gof is a minor tributary of the river. It starts near the small village of Llantrithyd near the A48
A48 road
The A48 is a major trunk road in Great Britain. It runs from the A40 at Highnam west of Gloucester to the A40 at Carmarthen. Before the construction of the M4 motorway and the first Severn Bridge in the mid 1960s it was the principal route into South Wales. For most of its journey through Wales,...
and flows southwest for nearly 3 miles, through the hamlet of Treguff (this name is a corruption of Tre-gof). Its confluence with the Thaw is nearly opposite that of the Nant y Stepsau.
The Nant Aberthin is the smallest named tributary. It flows through the small village of Aberthin
Aberthin
Aberthin is a small village, just outside Cowbridge in the Vale of Glamorgan, South Wales.- Amenities :It has no shops, but does have two pubs, a village hall which when built in 1749 was created as Wales's second purpose-built Calvinistic Methodist meeting house, and a very special tree.It is...
, and is under a mile long. Its actual name is Nant y Berthyn - Aberthin is a corruption of this name.
An unnamed brook flows through St Athan
St Athan
St Athan is a village and community in the Vale of Glamorgan in South Wales.-History and amenities:The English name is a corruption of the Welsh female Saint Tathan, described by Iolo Morgannwg as the daughter of the King of Gwent. The village and parish church is dedicated to St Tathan. There are...
. Its length is approximately 1.5 miles, and it joins the Thaw near its mouth.
The Nant Llanmihangel is over a mile long. It comes from Llanmihangel, and flows into the river at Llandough
Llandough
Llandough is a village and southern suburb of Cardiff, in the Vale of Glamorgan, Wales.- Location :...
, south of Llanblethian.
There are many insignificant, and thus unnamed, tributaries of the Thaw. One flows in the same direction of the Thaw for a mile or so, and flows amongst a dismantled railway and power cables. The stream in question meets the Thaw near the village of Flemingston and is very near the aforementioned Nant Tre-gof.
Flooding
On the 31st of October, 1998, water levels in the river went to the highest level recorded and the river flooded, causing significant damage to 4 properties in Cowbridge, 4 in Aberthin, and 17 in Llanblethian. The flooding was caused by "floodwater overtopping the banks of main rivers and ordinary watercourses, and restrictions to flow in channels and subcharging of drains", meaning that debris and other obstructions blocked the river's flow.Estuary
The river meets the Bristol ChannelBristol Channel
The Bristol Channel is a major inlet in the island of Great Britain, separating South Wales from Devon and Somerset in South West England. It extends from the lower estuary of the River Severn to the North Atlantic Ocean...
at a shingle beach called Leys Beach, at Breaksea Point
Breaksea Point
Breaksea Point is the southernmost point of mainland Wales .- Location :Breaksea Point is located in the Vale of Glamorgan and is part of the Heritage Coast of South Wales....
, one of the southernmost points of Wales. It flows through the village of Aberthaw
Aberthaw
Aberthaw is a village of the Vale of Glamorgan west of Barry on the coast of South Wales.The village is split into two halves - East Aberthaw and West Aberthaw, separated by the River Thaw. It is home to Aberthaw Cement Works and Aberthaw Power Station a coal power station plant that was linked to...
. At its mouth is the Aberthaw Power Station, which is split into two complexes, Aberthaw A and Aberthaw B, on the opposite sides of the river. When Aberthaw A first opened in February 1966, it was the most advanced power station in the world. Aberthaw B opened in the 1970s. The power station currently burns coal with a generating capacity 1455 megawatts, and proposals for a nuclear power station on the site were rejected due to close proximity to Cardiff
Cardiff
Cardiff is the capital, largest city and most populous county of Wales and the 10th largest city in the United Kingdom. The city is Wales' chief commercial centre, the base for most national cultural and sporting institutions, the Welsh national media, and the seat of the National Assembly for...
. Aberthaw A was subsequently demolished in 1995.
For centuries, an active, albeit small, port stood at the river's mouth, and provided docking facilities. In those days, the river was large and navigable by ships for some considerable distance; however, the river began silting up some time in the late 18th century. Its flow and size were so badly degraded that shipping was restricted to a few small vessels, but by 1850 it was of no use at all to shipping as it had become no more than a large stream. The port was abandoned altogether by 1900.
The Thaw was used to cool the power station, which led to a small amount of thermal pollution in the river's mouth. The estuary is not natural, because the river was diverted into a channel to allow the power station to be built, similar to the Cadoxton River
Cadoxton River
The Cadoxton River is a short river in the Vale of Glamorgan, South Wales and with a length of about 5 miles/8 kilometres it is one of Wales's shortest rivers.-Course:...
a few miles east. The river's original mouth was actually slightly further east of here; many lagoons, small pools and saltmarshes are left over from its once large estuary.