River Mellte
Encyclopedia
The River Mellte is a river in Wales
. It is formed by the confluence of the Afon Llia
and the Afon Dringarth
. It then flows south through the village of Ystradfellte
to Pontneddfechan where it joins with the Nedd Fechan
to become the River Neath
. The river derives its name from Mellt - the Welsh word for 'lightning' - after its tendency to rise and fall rapidly in response to heavy rainfall.
as it crosses the Carboniferous Limestone
outcrop. It resurges at the Blue Pool. There are fifteen known entrances to the cave system which is also known as 'White Horse Cave' after the supposed resemblance to a horse of a flowstone feature near its main entrance. It is a complex maze of passageways, large and small, mostly developed along one or two major bedding planes. In extreme flood conditions the entire cave can flood to the roof. It is used heavily by school and adventure groups though sections of the cave can be hazardous for the unwary. There have been a number of fatalities over the years.
(Dyffrynoedd Nedd a Mellte a Moel Penderyn SSSI) and as a special area of conservation
(Coedydd Nedd a Mellte SAC) in respect of the bryophyte
flora which the deep and wooded nature of the valleys help to support.
and the Countryside Council for Wales
to ensure that the path erosion that has resulted from the popularity of this area is halted and reversed. A concessionary path runs through the gunpowder works site.
Visitors can park at the pay and display car parks at Cwm Porth and the nearby Gwaun Hepste or else in Pontneddfechan.
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...
. It is formed by the confluence of the Afon Llia
Afon Llia
The Afon Llia is a short river in Powys, Wales and which is wholly contained within the Brecon Beacons National Park.Several streams draining the eastern slopes of Fan Nedd and the western slopes of Fan Dringarth in the Fforest Fawr section of the national park meet to form the river which then...
and the Afon Dringarth
Afon Dringarth
The Afon Dringarth is a river in Powys, Wales and wholly contained within the Brecon Beacons National Park. Its headwater streams drain the eastern slopes of Fan Dringarth, the southern slopes of Craig Cerrig-gleisiad and the western slopes of Fan Fawr...
. It then flows south through the village of Ystradfellte
Ystradfellte
Ystradfellte is a small village in Powys, Wales, in the Fforest Fawr area of the Brecon Beacons National Park.Because of the geography and topography of the area the village of Ystradfellte is not visible from the nearest main road, the A4059 Hirwaun to A470 stretch.Ystradfellte comes under...
to Pontneddfechan where it joins with the Nedd Fechan
Nedd Fechan
The Nedd Fechan or 'Little Neath' is a river in the county of Powys, south Wales, Great Britain. It rises on the eastern slopes of Fan Gyhirych in the Fforest Fawr section of the Brecon Beacons National Park and flows south for 12km / 7 mi to join with the Afon Mellte at Pontneddfechan, their...
to become the River Neath
River Neath
River Neath is a river in south Wales running south west from its source in the Brecon Beacons National Park to its mouth at Baglan Bay below Briton Ferry on the east side of Swansea Bay.Several minor rivers rise on the southern slopes of Fforest Fawr...
. The river derives its name from Mellt - the Welsh word for 'lightning' - after its tendency to rise and fall rapidly in response to heavy rainfall.
Underground section
The entire river runs underground for 1/4 mile at Porth yr OgofPorth yr Ogof
Porth yr Ogof is a cave located near the village of Ystradfellte, near the southern boundary of the Brecon Beacons National Park in Wales. In 1998 the cave's passageways had been measured as over 2.25 km in length. Among the cave's fifteen entrances is the largest cave entrance in Wales...
as it crosses the Carboniferous Limestone
Carboniferous limestone
Carboniferous Limestone is a term used to describe a variety of different types of limestone occurring widely across Great Britain and Ireland which were deposited during the Dinantian epoch of the Carboniferous period. They were formed between 363 and 325 million years ago...
outcrop. It resurges at the Blue Pool. There are fifteen known entrances to the cave system which is also known as 'White Horse Cave' after the supposed resemblance to a horse of a flowstone feature near its main entrance. It is a complex maze of passageways, large and small, mostly developed along one or two major bedding planes. In extreme flood conditions the entire cave can flood to the roof. It is used heavily by school and adventure groups though sections of the cave can be hazardous for the unwary. There have been a number of fatalities over the years.
Waterfalls
Downstream of Porth-yr-Ogof and within 'Waterfalls Country', the river flows over several falls, the most significant of which are Sgwd Clun-gwyn, Sgwd Isaf Clun-gwyn and Sgwd y Pannwr - respectively 'white meadow fall', 'lower white meadow fall' and 'fall of the woollen washer (or fuller)' in English.Habitat protection
The larger part of the river and its valley is protected both as a site of special scientific interestSite of Special Scientific Interest
A Site of Special Scientific Interest is a conservation designation denoting a protected area in the United Kingdom. SSSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in Great Britain are based upon...
(Dyffrynoedd Nedd a Mellte a Moel Penderyn SSSI) and as a special area of conservation
Special Area of Conservation
A Special Area of Conservation is defined in the European Union's Habitats Directive , also known as the Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora...
(Coedydd Nedd a Mellte SAC) in respect of the bryophyte
Bryophyte
Bryophyte is a traditional name used to refer to all embryophytes that do not have true vascular tissue and are therefore called 'non-vascular plants'. Some bryophytes do have specialized tissues for the transport of water; however since these do not contain lignin, they are not considered to be...
flora which the deep and wooded nature of the valleys help to support.
Industrial Archaeology
The river provided the source of the power for the former gunpowder works at Pontneddfechan. The site is strung out along 2 miles of the valley on both sides of the river. The remains of two weirs from which leats took water to drive a series of waterwheels and turbines can still be seen. All production on the site ceased in 1931.Access
Much of the river is accessible to walkers with both public footpaths and concessionary paths running beside the river and giving access to the various falls. Brecon Beacons National Park Authority is working in conjunction with the Forestry CommissionForestry Commission
The Forestry Commission is a non-ministerial government department responsible for forestry in Great Britain. Its mission is to protect and expand Britain's forests and woodlands and increase their value to society and the environment....
and the Countryside Council for Wales
Countryside Council for Wales
The Countryside Council for Wales is an Assembly Government Sponsored Body. It is the Welsh Assembly Government's wildlife conservation authority for Wales...
to ensure that the path erosion that has resulted from the popularity of this area is halted and reversed. A concessionary path runs through the gunpowder works site.
Visitors can park at the pay and display car parks at Cwm Porth and the nearby Gwaun Hepste or else in Pontneddfechan.