Lough Allen (Irish: Loch Aillionn)[2] is a lake on the River Shannon[3] in northeastern Connacht, Ireland. Most of the lake is in County Leitrim,[3] with a smaller part in County Roscommon. 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 and Lough Derg are much further to the south.

Lough Allen
Lough Allen Spencer Harbour 2003 09 11.jpg
Spencer Harbour
Lough Allen is located in island of Ireland
Lough Allen
Lough Allen
LocationCounty Leitrim
Coordinates54°06′25″N 8°02′21″W / 54.10694°N 8.03917°W / 54.10694; -8.03917Coordinates: 54°06′25″N 8°02′21″W / 54.10694°N 8.03917°W / 54.10694; -8.03917
Native nameLoch Aillionn (Irish)
Primary inflowsRiver Shannon
Primary outflowsRiver Shannon
Basin countriesIreland
Max. length17.7 km (11.0 mi)
Max. width4.8 km (3.0 mi)
Surface area35 km2 (14 sq mi)[1]
Average depth4–5 m (13–16 ft)[1]
Max. depth31 m (102 ft)[1]
IslandsCorry Island, Drummans Island, Inishmagrath
SettlementsArigna, Ballinaglera, Corry, Drumshanbo, Drumkeeran, Dowra, Keadue


Lough Allen, out of which the Shannon takes its source, is nine miles long, and three miles wide.[4] The lake is shaped like an isosceles triangle. 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 (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,[5] from Ballinagleragh to Drumshanbo. 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.[6]


Between c. 2001 – c. 2003, water quality was reported to be excellent with an oligotrophic rating.[7][n 1] The pike population is the "native Irish strain" (Irish: liús meaning 'Irish Pike') not the other European Pike strain (Irish: gailliasc meaning 'strange or foreign fish').[9] The ecology of Lough Allen, and other Irish waterways, remain threatened by curly waterweed, zebra mussel, and freshwater clam invasive species.[9][10]


Significant traces of Mesolithic inhabitation have been found around the lakeshore, with hundreds of stone tools collected.[11][12] 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.[12] 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.[13]



Iron ore has been extracted at Slieve Anierin for millennia.[14] 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 in boats of up to forty tons. During the Irish Rebellion of 1641 nearly all ironworks were destroyed, but many were revived by the English after the Irish Confederate Wars.[15] Extensive forests around Lough Allen before the 17th century were denuded to make charcoal for ironworks,[16] the industry later collapsing in the 19th century.


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.[17]


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'.[18] 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.[19]


See alsoEdit

References and notesEdit


  1. ^ Trophic states of "Oligotrophic" and "Mesotrophic" are desirable, but freshwater lakes rated 'Eutrophic' or 'Hypertrophic' indicates pollution.[8]

Primary sourcesEdit

  1. ^ a b c d Jahncke, Michael J.; Garrett, E. Spencer; Reilly, Alan; Martin, Roy E.; Cole, Emille, eds. (2002). Public, Animal, and Environmental Aquaculture Health Issues. Wiley. p. 92. ISBN 0-471-38772-X. Archived from the original on 24 September 2021. Retrieved 20 December 2020.
  2. ^ "Placenames Database of Ireland". Archived from the original on 19 February 2021. Retrieved 10 April 2012.
  3. ^ a b Bord Failte (2001). Bord Failte Ireland Guide, 4th Edition. New York: St. Martin's Griffin. p. 775. ISBN 0-312-27048-8. Archived from the original on 24 September 2021. Retrieved 20 December 2020.
  4. ^ Boate 1653, pp. 74.
  5. ^ Bord Failte (2001). Bord Failte Ireland Guide, 4th Edition. New York: St. Martin's Griffin. p. 779. ISBN 0-312-27048-8. Archived from the original on 24 September 2021. Retrieved 20 December 2020.
  6. ^ "Ireland on the verge of an oil and gas bonanza". Irish Independent. 20 May 2007. Archived from the original on 1 March 2011. Retrieved 11 June 2009.
  7. ^ Clenaghan, Clinton & Crowe 2005, pp. 97.
  8. ^ Clenaghan, Clinton & Crowe 2005, pp. 8.
  9. ^ a b Pedreschi, Debbi; Kelly‐Quinn, Mary; Caffrey, Joe; O'Grady, Martin; Mariani, Stefano (2014). Phillimore, Albert (ed.). "Genetic structure of pike ( E sox lucius ) reveals a complex and previously unrecognized colonization history of I reland". Journal of Biogeography. 41 (3): 548–560. doi:10.1111/jbi.12220. ISSN 0305-0270. PMC 4238397. PMID 25435649.
  10. ^ Clenaghan, Clinton & Crowe 2005, pp. 16.
  11. ^ Driscoll, Killian (2006). The early prehistory in the west of Ireland: Investigations into the social archaeology of the Mesolithic, west of the Shannon, Ireland. Archived from the original on 9 April 2017. Retrieved 8 April 2017.
  12. ^ a b Driscoll, Killian; Menuge, Julian; O'Keeffe, Emmett (2014). "New materials, traditional practices: a Mesolithic silicified dolomite toolkit from Lough Allen, Ireland". Proceedings of the Royal Irish Academy. 114C. Archived from the original on 9 April 2017. Retrieved 8 April 2017.
  13. ^ Cooney, G; Mandal, S (1998). The Irish Stone Axe Project: Monograph I. Bray: Wordwell. ISBN 1869857232.
  14. ^ Boate 1653, pp. 128.
  15. ^ Boate 1653, pp. 129.
  16. ^ Boate 1653, pp. 120.
  17. ^ Delany, Ruth (2004). Ireland's Inland Waterways. Appletree Press. p. 133.
  18. ^ Alf Delany archives
  19. ^ Water Wag Newsletter 2015

Secondary sourcesEdit

  • Clenaghan, Conor; Clinton, Frank; Crowe, Matthew (2005). Phosphorus Regulations National Implementation Report (PDF) (Report). Environmental Protection Agency, Office of Environmental Enforcement. Archived (PDF) from the original on 25 October 2017. Retrieved 9 February 2017.
  • Pedreschi, D.; Kelly-Quinn, M.; Caffrey, J; O'Grady, M.; Mariani, S.; Phillimore, A. (2014), "Genetic structure of pike (Esox lucius) reveals a complex and previously unrecognized colonization history of Ireland", Journal of Biogeography, Journal of Biogeography, 41(3), 548–560., 41 (3): 548–560, doi:10.1111/jbi.12220, PMID 25435649, S2CID 13486116
  • Boate, Gerard (1653). Irelands Naturall History (Digitized 2009 ed.). Samuell Hartlib, For the Common Good of Ireland, and more especially, for the benefit of the Adventurers and Planters therein; Imprinted at London for John Wright at the Kings Head, in the Old Bayley. Archived from the original on 24 February 2017. Retrieved 24 February 2017.