The Afon Rheidol is a river in

Ceredigion Ceredigion ( , , ) is a county in the west of Wales, corresponding to the historic county of Cardiganshire. During the second half of the first millennium Ceredigion was a minor kingdom. It has been administered as a county since 1282. Cer ...

, Wales, in length. The source is Plynlimon. Receiving an average annual rainfall of , Plynlimon is also the source of both the Wye and the

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Geography and geology

The Rheidol rises in the headwaters of the Nant-y-moch Reservoir on the western flanks of Plynlimon, near the sources of the Wye and

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. After flowing south to Ponterwyd on the increasingly deep valley, then southwest through Welsh Oak

ancient woodland In the United Kingdom, an ancient woodland is a woodland that has existed continuously since 1600 or before in England, Wales and Northern Ireland (or 1750 in Scotland). Planting of woodland was uncommon before those dates, so a wood present in 16 ...

, it veers westwards to its confluence with the Afon Mynach, at

Devil's Bridge, Ceredigion Devil's Bridge ( cy, Pontarfynach, lit. "The bridge on the Mynach") is a village and community in Ceredigion, Wales. Above the River Mynach on the edge of the village is the unusual road bridge from which the village gets its English name ...

( cy, Pontarfynach, lit. "bridge on the Mynach") and a spectacular waterfall. The river continues passing the abandoned workings of the Cwm Rheidol

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, ...

mine; one of many other metal mines in the valleya source of extracted metal pollution of the river and flows westwards before its

confluence In geography, a confluence (also: ''conflux'') occurs where two or more flowing bodies of water join to form a single channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river (main stem); o ...

with the

Afon Ystwyth The River Ystwyth (; cy, Afon Ystwyth "winding river") is a river in Ceredigion, Wales. The length of the main river is . Its catchment area covers . Its source is a number of streams that include the Afon Diliw, located on the west slopes of ...

and the

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

Aberystwyth Aberystwyth () is a university and seaside town as well as a community in Ceredigion, Wales. Located in the historic county of Cardiganshire, means "the mouth of the Ystwyth". Aberystwyth University has been a major educational location i ...

to drain into

Cardigan Bay Cardigan Bay ( cy, Bae Ceredigion) is a large inlet of the Irish Sea, indenting the west coast of Wales between Bardsey Island, Gwynedd in the north, and Strumble Head, Pembrokeshire at its southern end. It is the largest bay in Wales. Geo ...

. In the late 1960s, when the mine was closed, a major blowout of water contained in an

adit An adit (from Latin ''aditus'', entrance) is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, ventilated, and minerals extracted at the lowest convenient level. Adit ...

coloured the whole river an

ochre Ochre ( ; , ), or ocher in American English, is a natural clay earth pigment, a mixture of ferric oxide and varying amounts of clay and sand. It ranges in colour from yellow to deep orange or brown. It is also the name of the colours produced ...

orange colour and greatly added to the concentrations of lead and zinc in the river. Today, management of water still draining from the mine is by the use of constructed wetlands. Previous management had included a limestone filter bed installed in the 1960s and now redundant. The filter bed is still in place and can be seen from the road.

Environment

The catchment of the Rheidol is dominated by the western maritime exposure of this part of Wales. Rainfall levels are high and

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

s reflect both high rainfall and the acidic nature of the underlying rocks. Combined with the

acid mine drainage Acid mine drainage, acid and metalliferous drainage (AMD), or acid rock drainage (ARD) is the outflow of acidic water from metal mines or coal mines. Acid rock drainage occurs naturally within some environments as part of the rock weathering ...

from abandoned silver and lead mines that sit within the catchment (the area around Aberystwyth contains 38 of the 50 worst polluting metal mines in Wales), by 1991 the river had regularly broken

EEC The European Economic Community (EEC) was a regional organization created by the Treaty of Rome of 1957,Today the largely rewritten treaty continues in force as the ''Treaty on the functioning of the European Union'', as renamed by the Lis ...

pollution limits for heavy metal contamination such as

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

. Upland '' Molinia'' spp. grassland is common growing on deep deposits of

peat Peat (), also known as turf (), is an accumulation of partially Decomposition, decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, Moorland, moors, or muskegs. The peatland ecosystem covers and ...

. Within the valleys, dense and ancient oak forests with rich understoreys of

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta ('' sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and ...

es and

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. For many centuries the economy of the Rheidol valley had been metal mining. This has now been replaced by

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

ry,

tourism Tourism is travel for pleasure or business; also the theory and practice of touring (disambiguation), touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tour (disambiguation), tours. Th ...

and the farming of

beef Beef is the culinary name for meat from cattle (''Bos taurus''). In prehistoric times, humankind hunted aurochs and later domesticated them. Since that time, numerous breeds of cattle have been bred specifically for the quality or quantit ...

dairy cattle Dairy cattle (also called dairy cows) are cattle bred for the ability to produce large quantities of milk, from which dairy products are made. Dairy cattle generally are of the species '' Bos taurus''. Historically, little distinction was ...

and

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticate ...

. There are a number of tourist attractions in the Rheidol valley. These include the Devil's Bridge waterfalls where three bridges, each built over the previous, span the top of a most spectacular waterfall. Between Devil's Bridge and Aberystwyth runs a narrow-gauge steam railway - the Vale of Rheidol Railway. This was originally built to ship metal ore from the mines but now provides a very popular tourist route into the top end of the Rheidol valley. A large stag shape on the valley wall is a

scheduled ancient monument In the United Kingdom, a scheduled monument is a nationally important archaeological site or historic building, given protection against unauthorised change. The various pieces of legislation that legally protect heritage assets from damage and d ...

and is supposedly one of two stag hill figures in the United Kingdom, the other being at

Mormond Hill Mormond Hill (Scottish Gaelic A' Mhormhonadh, meaning the great hill or moor; known as ''Mormounth'' in Old Scots) is a large hill in Aberdeenshire, Scotland, not far from Fraserburgh. Its peak is .lead mining waste feature which merely resembles a stag and not a true

hill figure A hill figure is a large visual representation created by cutting into a steep hillside and revealing the underlying geology. It is a type of geoglyph usually designed to be seen from afar rather than above. In some cases trenches are dug and ...

. The spoil from the Gelli mine was initially poured down the valley side to form the 'head and horns'. When the mine reopened at the turn of the 20th Century for zinc production, a tramway was built along the base of the original spoil and across. The dumping of spoil from this venture created the body and legs."WHITE STAG, RHEIDOL VALLEY" at coflein.gov.uk
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References

{{Authority control Aberystwyth Elenydd Rheidol