Lough Allen () is a

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

on the

River Shannon The River Shannon ( ga, Abhainn na Sionainne, ', '), at in length, is the longest river in the British Isles. It drains the Shannon River Basin, which has an area of , – approximately one fifth of the area of the island of Ireland. The Sha ...

in northeastern

Connacht Connacht ( ; ga, Connachta or ), is one of the provinces of Ireland, in the west of Ireland. Until the ninth century it consisted of several independent major Gaelic kingdoms ( Uí Fiachrach, Uí Briúin, Uí Maine, Conmhaícne, and ...

Ireland Ireland ( ; ga, Éire ; Ulster-Scots: ) is an island in the North Atlantic Ocean, in north-western Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the s ...

. Most of the lake is in

County Leitrim County Leitrim ( ; gle, Contae Liatroma) is a county in Ireland. It is in the province of Connacht and is part of the Northern and Western Region. It is named after the village of Leitrim. Leitrim County Council is the local authority for the ...

, with a smaller part in

County Roscommon "Steadfast Irish heart" , image_map = Island of Ireland location map Roscommon.svg , subdivision_type = Sovereign state, Country , subdivision_name = Republic of Ireland, Ireland , subdivision_type1 = Provinces of I ...

. The lake lies to the south of the River Shannon's source, near the Iron Mountains, and is the uppermost of the three main lakes on the river. The other two,

Lough Ree Lough Ree () is a lake in the midlands of Ireland, the second of the three major lakes on the River Shannon. Lough Ree is the second largest lake on the Shannon after Lough Derg. The other two major lakes are Lough Allen to the north, and L ...

and Lough Derg are much further to the south.

Geography

Lough Allen, out of which the Shannon takes its source, is nine miles long, and three miles wide. The lake is shaped like an

isosceles triangle In geometry, an isosceles triangle () is a triangle that has two sides of equal length. Sometimes it is specified as having ''exactly'' two sides of equal length, and sometimes as having ''at least'' two sides of equal length, the latter versio ...

. The Shannon enters the lake at the wider northern end and leaves the lake at the narrow southern end. Other rivers that feed the lake include the Diffagher (northwest), the

Yellow Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In th ...

(northeast), the Stoney (east) and the Arigna (southwest). The R280 regional road skirts the west side of the lake, while the R207 follows the east bank, from Ballinagleragh to

Drumshanbo Drumshanbo (, ridge of the old huts) is a small town situated in the heart of County Leitrim, Ireland. Drumshanbo is surrounded by a scenic area of soft rolling hills, woodlands, lakes and the Sliabh an Iarainn and Arigna mountains. It is a wel ...

. The R200 road is on the north side of the lake, traveling west from Dowra to Drumkeeran. Slieve Anierin lie to the east of Lough Allen. There has been speculation that notable reserves of oil and gas lie beneath the Allen basin.

Ecology

Between , water quality was reported to be excellent with an

oligotrophic An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments. Oligotrophs are characterized by slow growth, low rates o ...

rating. The pike population is the "native Irish strain" ( ga, liús meaning 'Irish Pike') not the other European Pike strain ( ga, gailliasc meaning 'strange or foreign fish'). The ecology of Lough Allen, and other Irish waterways, remain threatened by curly waterweed,

zebra mussel The zebra mussel (''Dreissena polymorpha'') is a small freshwater mussel. The species originates from the lakes of southern Russia and Ukraine, but has been accidentally introduced to numerous other areas and has become an invasive species in ma ...

, and

freshwater clam Freshwater bivalves are one kind of freshwater mollusc, along with freshwater snails. They are bivalves that live in fresh water as opposed to salt water, which is the main habitat type for bivalves. The majority of species of bivalve molluscs ...

invasive species.

Prehistory

Significant traces of Mesolithic inhabitation have been found around the lakeshore, with hundreds of stone tools collected. In total almost 1000 stone tools were collected during a set of surveys by Killian Driscoll, and 95% were formed on silicified dolomite, which outcrops locally. The remaining 5% were formed from flint, chert and quartz, along with the shale/mudstone and basalt ground/polished axes. The majority of the stone tools are characteristic of the Later Mesolithic, with possible evidence for the Early Mesolithic and limited evidence for Neolithic activity. The assemblage includes a number of stone axes and axe roughouts, and the roughouts represent the first recorded, by the Irish Stone Axe Project, as found in a lakeside context in Ireland, with most previously provenanced examples coming from axe quarry sites.

History

Ironworks

Iron ore Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the ...

has been extracted at Slieve Anierin for millennia. From the early 17th century a number of mines and works were conveniently contiguous to Lough Allen, allowing for the transportation of iron ore over water to the

ironworks An ironworks or iron works is an industrial plant where iron is smelted and where heavy iron and steel products are made. The term is both singular and plural, i.e. the singular of ''ironworks'' is ''ironworks''. Ironworks succeeded bloomer ...

in boats of up to forty tons. During the

Irish Rebellion of 1641 The Irish Rebellion of 1641 ( ga, Éirí Amach 1641) was an uprising by Irish Catholics in the Kingdom of Ireland, who wanted an end to anti-Catholic discrimination, greater Irish self-governance, and to partially or fully reverse the plantat ...

nearly all ironworks were destroyed, but many were revived by the English after the

Irish Confederate Wars The Irish Confederate Wars, also called the Eleven Years' War (from ga, Cogadh na hAon-déag mBliana), took place in Ireland between 1641 and 1653. It was the Irish theatre of the Wars of the Three Kingdoms, a series of civil wars in the kin ...

. Extensive forests around Lough Allen before the 17th century were denuded to make charcoal for ironworks, the industry later collapsing in the 19th century.

Reservoir

On the construction of the Shannon hydroelectric scheme in 1925–9, the lake became a storage reservoir for the power station nearly 100 miles away, with sluices to control the flow into the river. This helps to maintain the flow during dry periods and manage flooding at other times. It made the Lough Allen Canal, which was rarely used by this time, unusable until restored in 1996.

Regattas

In the mid-19th century, regattas were held by M. O'Conor at Lough Allen Island which is also known as O'Reilly's Island at the southern end of the lake. The house is destroyed, and only a ruin now exists. Regatta parties were held at Birchill's House, Blackrock. E.K. Tenison of Kilronan Castle, the photographer, Captain Tottenham, Captain Birchill and Francis la Touche attended the Regatta parties. Among the yachts competing in the regattas were 'Corsair', 'Avenger', 'Querida', 'Meta' and 'Shamrock'. The Water Wags from Dun Laoghaire, organised a regatta on Lough Allen, in September 2015, for their 14'-3" long historic open clinker dinghies. competed in a regatta in 2014, including Penelope (1933), Scallywag, Swift, Moosmie (1910), Mollie, Chloe, Marie Louise (1927) and Good Hope. This was probably the first regatta on the lake since the mid-19th century.Water Wag Newsletter 2015

Recreation

References and notes

Notes

Primary sources

Secondary sources

* * * {{DEFAULTSORT:Allen Lakes of County Leitrim Lakes of County Roscommon River Shannon