Seathwaite Tarn
Encyclopedia
Seathwaite Tarn is a reservoir
in the Furness Fells
within the English Lake District
. It is located to the south of Grey Friar
and to the west of Brim Fell
(on the ridge between The Old Man of Coniston and Swirl How
) and north east of the village of Seathwaite on the east of the Duddon Valley
.
In order to create a source of drinking water the existing tarn was considerably enlarged with a dam
in 1904. During the dam construction some of the navvies rioted damaging buildings in the village, several rioters were shot, one dying the next day.
The dam is almost 400 yards (366 m) long and is concrete
cored with slate
buttress
es, the resulting depth of the tarn
being around 80 feet (24 m). Water is not abstracted directly from the tarn, but flows some distance downriver to an off-take weir
.
On the slopes of Brim Fell, above the head of the reservoir, are the remains of Seathwaite Tarn Mine. This was worked for copper
in the mid 19th century, and also appears as a location in the novel The Plague Dogs
by Richard Adams
. Rocks in the area were the first confirmed occurrence of wittichenite in the British Isles
.
Bronze Age
ring cairn
s were found close to Seathwaite Tarn in 2003, these were excavated in 2003 and 2007.
Seathwaite Tarn has suffered from acidification. An experiment in 1992–1993 to reduce the acidification by using a phosphorus
-based fertiliser increased the pH from 5.1 to 5.6 and changed the levels of the different species of the rotifer
assemblage significantly.
Reservoir
A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...
in the Furness Fells
Furness Fells
The Furness Fells are those hills and mountains in the Furness region of Cumbria, England. Historically part of Lancashire, the Furness Fells or High Furness is the name given to the upland part of Furness, that is, that part of Furness lying north of the line between Ulverston and Ireleth...
within the English Lake District
Lake District
The Lake District, also commonly known as The Lakes or Lakeland, is a mountainous region in North West England. A popular holiday destination, it is famous not only for its lakes and its mountains but also for its associations with the early 19th century poetry and writings of William Wordsworth...
. It is located to the south of Grey Friar
Grey Friar
Grey Friar is a fell in the English Lake District, it is one of the Coniston Fells and is situated 13 kilometres west-south-west of Ambleside. It reaches a height of 770 metres and stands to the north west of the other Coniston Fells, a little off the beaten track and tends to be the least visited...
and to the west of Brim Fell
Brim Fell
Brim Fell is a fell in the English Lake District. It stands to the west of Coniston village in the southern part of the District.-Topography:The Coniston Fells form the watershed between Coniston Water and the Duddon valley to the west...
(on the ridge between The Old Man of Coniston and Swirl How
Swirl How
Swirl How is a fell in the English Lake District. It stands between Coniston and the Duddon Valley in the southern part of the District.The Coniston Fells form the watershed between Coniston Water and the Duddon valley to the west. The range begins at Wrynose Pass and runs south for around...
) and north east of the village of Seathwaite on the east of the Duddon Valley
Duddon Valley
The Duddon Valley is a valley in the Lake District National Park in Cumbria, England. The River Duddon flows through the valley, rising in the mountains between Eskdale and Langdale, before flowing into the Irish Sea near Broughton in Furness...
.
In order to create a source of drinking water the existing tarn was considerably enlarged with a dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
in 1904. During the dam construction some of the navvies rioted damaging buildings in the village, several rioters were shot, one dying the next day.
The dam is almost 400 yards (366 m) long and is concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
cored with slate
Slate
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. The result is a foliated rock in which the foliation may not correspond to the original sedimentary layering...
buttress
Buttress
A buttress is an architectural structure built against or projecting from a wall which serves to support or reinforce the wall...
es, the resulting depth of the tarn
Tarn
Tarn is a department of 5,758 km2 in the Midi-Pyrénées region in the southwest of France, named after the Tarn River. It was formed in 1790 of the three dioceses of Albi, Castres and Lavaur, belonging to the province of Languedoc. In 1906, the population was 330,533...
being around 80 feet (24 m). Water is not abstracted directly from the tarn, but flows some distance downriver to an off-take weir
Weir
A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...
.
On the slopes of Brim Fell, above the head of the reservoir, are the remains of Seathwaite Tarn Mine. This was worked for copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
in the mid 19th century, and also appears as a location in the novel The Plague Dogs
The Plague Dogs
The Plague Dogs is the third novel by Richard Adams, author of Watership Down, about two dogs who escape an animal testing facility and are subsequently pursued by both the government and the media...
by Richard Adams
Richard Adams
Richard Adams was a non-conforming English Presbyterian divine, known as author of sermons and other theological writings.-Life:...
. Rocks in the area were the first confirmed occurrence of wittichenite in the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
.
Bronze Age
Bronze Age
The Bronze Age is a period characterized by the use of copper and its alloy bronze as the chief hard materials in the manufacture of some implements and weapons. Chronologically, it stands between the Stone Age and Iron Age...
ring cairn
Cairn
Cairn is a term used mainly in the English-speaking world for a man-made pile of stones. It comes from the or . Cairns are found all over the world in uplands, on moorland, on mountaintops, near waterways and on sea cliffs, and also in barren desert and tundra areas...
s were found close to Seathwaite Tarn in 2003, these were excavated in 2003 and 2007.
Seathwaite Tarn has suffered from acidification. An experiment in 1992–1993 to reduce the acidification by using a phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
-based fertiliser increased the pH from 5.1 to 5.6 and changed the levels of the different species of the rotifer
Rotifer
The rotifers make up a phylum of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John Harris in 1696, and other forms were described by Anton van Leeuwenhoek in 1703...
assemblage significantly.