Shannon River Basin Explained

The Shannon River Basin consists of the area containing Ireland's longest river, the River Shannon, and all of its tributaries and lakes. The official Ordnance Survey Ireland length of the Shannon from its Shannon Pot source is made up of tidal water flow and freshwater flow.^[1]

Statistics

The Shannon Basin is Ireland's largest basin with an area of 11700km2. Including the estuary and the River Feale, the total catchment drains a total of 16865km2.^[2]

It has a Long Term Average Flow of 208.1m3/s (at Limerick City).^[3] This is double the flow rate of Ireland's second largest river, the River Corrib (104.8abbr=onNaNabbr=on).^[3] If the discharges from all of the rivers and streams into the Shannon Estuary (including the rivers Feale 34.6 m³/s, Maigue 15.6 m³/s, Fergus 25.7 m³/s, and Deel 7.4 m³/s)^{[4] [5]} are added to the discharge at Limerick, the total discharge of the River Shannon at its mouth at Loop Head reaches 300m3/s.

The River Shannon is a traditional freshwater river for just 45% of its total length. Excluding the 63.5miles tidal estuary from its total length of, if one also excludes the lakes (L. Derg 24 mi, L. Ree 18 mi, L. Allen 7 mi^[6] plus L. Boderg, L. Bofin, L. Forbes, L. Corry) from the Shannon's freshwater flow of, the Shannon as a freshwater river is only about long.

The Shannon River Basin is part of the Shannon International River Basin District (SHIRBD)^[7] administrative area which has an area of 17963km2 in area. In addition to the Shannon Basin, the district also covers coastal parts of counties Kerry and Clare which drain to the sea. The SHIRBD contains 7666km (4,763miles) of rivers, 1220km (760miles) of coastline including estuaries, and 113 lakes, including 53 over in size. The main land use throughout the SHIRBD area is agriculture (70.7%). Peatlands (11.1%) and forestry (3.2%) are also important. The SHIRBD's population is 618,884 at 34pd/km2 (Census data 2002).^[8]

Furthest sources

There are some tributaries within the River Shannon system which have headwaters that are further in length (from source to mouth) than the Shannon Pot source, such as the Owenmore River (County Cavan) in County Cavan, which flows west for 14.5km (09miles)^[9] through the valley of Glangevlin before joining the Shannon about 30NaN0 below the Shannon Pot at Lugnashinna,^[10] thus adding 110NaN0 to the Shannon's overall length, bringing it to 372km (231miles).

Also the Boyle River has a similar claim. The river flow from the furthest reaches of the Boyle catchment to Limerick city has a measurement of 290km (180miles).^[11] When added to the Shannon's 63.5abbr=onNaNabbr=on estuary this gives a total river flow of 392.1km (243.6miles), which makes it the longest river within the River Shannon basin (from source to mouth)—31.6km (19.6miles) longer than the Shannon Pot source. Thus the Boyle-Shannon river can be regarded as having the longest natural river flow in Ireland.^[12]

Geography

The River Shannon Basin touches more than half (17) of Ireland's counties:- Limerick, Clare, Tipperary, Offaly, Westmeath, Longford, Roscommon, Kerry, Galway, Leitrim, Cavan, Sligo, Mayo, Cork, Laois, Meath and Fermanagh.^[13]

Towns situated in the Shannon Basin

Towns and Villages (with 2011 populations^[14]) within the Shannon River Basin and the rivers and riverbanks on which they stand:

Shannon River

(going downstream)

• Dowra
• Drumshanbo (Lough Allen Canal – Left Bank) 857
• Leitrim Village (L. Bank) 485
• Carrick-on-Shannon 3,980
• Jamestown (L. Bank)
• Drumsna (L. Bank) 247
• Drumod (Lough Boderg – L. Bank) 356
• Roosky (Right Bank) 188
• Termonbarry (R. Bank) 366
• Cloondara (L. Bank)
• Lanesborough 1,388
• Athlone 20,153
• Clonmacnoise (L. Bank)
• Shannonbridge (L. Bank) 206
• Banagher (L. Bank) 1,653
• Portumna (R. Bank) 1,530
• Terryglass (Lough Derg – L. Bank)
• Mountshannon (Lough Derg – R. Bank) 152
• Dromineer (Lough Derg – L. Bank) 113
• Ballina (L. Bank) 2,442
• Killaloe (R. Bank) 1,292
• O'Briensbridge 235
• Castleconnell (L. Bank) 1,917
• Ardnacrusha
• Limerick City 87,081
• Shannon (S. Estuary – R. Bank) 9,673
• Kilrush (S. Estuary – R. Bank) 2,695
• Carrigaholt (S. Estuary – R. Bank)
• Foynes (S. Estuary – L. Bank) 543
• Glin (S. Estuary – L. Bank) 577
• Tarbert (S. Estuary – L. Bank) 551
• Ballylongford (S. Estuary – L. Bank) 418
• Ballybunion (S. Estuary – L. Bank) 1,354

Shannon River tributaries

• Boyle river: Boyle 2,588
• Lung river: Ballaghaderreen (outskirts) 1,822
• Camlin river: Longford 9,601
• Hind river: Roscommon (outskirts) 5,693
• River Inny (Leinster): Mullingar 20,103
• River Brosna: Ballymahon 1,563, Ferbane 1,165, Tullamore (Tullamore river) 14,361
• River Suck: Castlerea 1,985, Athleague 241, Ballinasloe 6,577
• Little Brosna river: Birr 5,452
• Ballyfinboy River: Borrisokane 1,145, Cloughjordan 511
• Nenagh river: Nenagh 8,439
• River Graney: Scariff 798
• Ratty river, also named Owengarney River or O'Garney River,^[15] : Sixmilebridge 1,839, Bunratty 219
• River Fergus: Ennis 25,360, Newmarket-on-Fergus 1,773
• River Maigue: Adare 1,106
• River Deel: Rathkeale 1,550, Askeaton 1,149
• River Feale: Listowel 4,338, Abbeyfeale 2,007

Tributary Sub Catchments

Freshwater Catchments (With Areas – km²) Going downstream

Left Bank:

• L Allen (upstream from L. Allen outlet) 415 km^2[2]
• Eslin River 73 km²
• River Rinn 311 km²
• Camlin River 352 km²
• River Inny (Leinster) 1,254 km²
• River Brosna 1,248 km²
• Little Brosna River 662 km²
• Ballyfinboy River 182 km²
• Nenagh River 321 km²
• Mulkear River 660 km^2[2]

Right Bank:

• Boyle River 725 km²
• Hind River 78 km²
• River Suck 1,600 km^2[16]
• Cappagh/Kilcrow 414 km²
• River Graney 295 km²

Estuarine Catchments Areas

Left Bank:

• River Maigue 1,000^2[2]
• River Deel 426 km^2[2]
• River Feale 1,170 km^2[2]

Right Bank:

• Bunratty River 233 km^2[2]
• River Fergus 1,043 km^2[2]

There are many other smaller tributaries which join the Shannon along its journey.

Lakes

There are a multitude of lakes within the Shannon River Basin, both on the main river and throughout the sub-catchments.

Here is a table showing the major lakes:

Lake	Area	Basin
Lough Derg	130 km2	Shannon
Lough Ree	105 km2	Shannon
Lough Allen	35 km2	Shannon
Lough Sheelin	19 km2	Inny
Lough Ennell	14.34 km2	Brosna
Lough Gara	11.9 km2	Boyle
Lough Derravaragh	10.8 km2	Inny
Lough Owel	10.3 km2	Brosna
Lough Bofin/Boderg/Scannal	9.7 km2[17]	Shannon
Lough Key	8.4 km2	Boyle
	3.7 km2	Graney
Lough Forbes	3 km2	Shannon
Lough Eidin (Drumharlow Lough)	2.7 km2	Boyle
Lough Funshinagh	2.5 km2[18]	Shannon

See also

• River Shannon
• Shannon Callows
• Rivers of Ireland
• List of rivers of Ireland
• List of loughs of Ireland

Notes and References

1. Web site: Ordnance Survey (Ireland) Educational Facts . 2014-10-09 . 2014-09-11 . https://web.archive.org/web/20140911001931/http://www.osi.ie/Education/Secondary-Schools/Teacher-Resources/Facts-%281%29.aspx . live .
2. Web site: Biology and Management of European Eel (Anguilla anguilla, L) in the Shannon Estuary, Ireland . https://web.archive.org/web/20140907173249/http://europeaneel.files.wordpress.com/2014/02/chapter-2-study-area.pdf . 2014-09-07 .
3. http://www.serbd.com/MultiDownloads/Creport/Chapters/Physical%20Description%20Ch3.pdf South Eastern River Basin Management: Page 38
4. Long-term effects of hydropower installations and associated river regulation on River Shannon eel populations: mitigation and management http://www.nuigalway.ie/faculties_departments/zoology/mccarthy/documents/mccarthy_et_al_2008.pdf
5. http://www.environ.ie/en/Publications/DevelopmentandHousing/Foreshore/FileDownLoad,30279,en.pdf SFPC Maintenance Dredging Application: Table 3-7
6. Web site: Ask about Ireland . 2014-10-09 . 2020-01-10 . https://web.archive.org/web/20200110054610/http://askaboutireland.ie/ . live .
7. Web site: Shannon River Basin District. https://web.archive.org/web/20160414222314/http://www.shannonrbd.com/. 2016-04-14. 2018-05-08.
8. http://www.dcenr.gov.ie/NR/rdonlyres/3A6F7001-9BED-4FAD-8E00-FBE2F7AEA042/0/ShIRBD191208.pdf Shannon International River Basin District Eel Management Plan
9. Ordnance Survey of Ireland: Rivers and their Catchment Basins 1958 (Table of Reference)
10. Book: Atlas and Cyclopedia of Ireland . P. W. Joyce . Cavan . 1900 . Murphy & McCarthy . 2014-10-09 . 2012-04-11 . https://web.archive.org/web/20120411192148/http://www.libraryireland.com/Atlas/Cavan.php . live .
11. Web site: River Habitat Survey, Fig. 2 . 2014-10-09 . 2014-09-13 . https://web.archive.org/web/20140913054555/http://www.riverhabitatsurvey.org/ . live .
12. Web site: European Commission Rivers Map . 2014-10-09 . 2015-08-19 . https://web.archive.org/web/20150819002433/http://ccm.jrc.ec.europa.eu/documents/ccm2mainrivers_map_100dpi.pdf . live .
13. Shannon Catchment-based Flood Risk Assessment and Management (CFRAM) Study. Page 3 http://shannoncframstudy.ie/docs/inception/UoM%2025%2026/Appendix%20B/TD_GNRL_0127_V1_0_JAC_HydroAssmtUoM2526_120917%20(Vol%201).pdf
14. Web site: Census 2011 – Population Classified by Area – Table 5 . 2014-10-12 . 2013-11-09 . https://web.archive.org/web/20131109181846/http://www.cso.ie/en/media/csoie/census/documents/census2011vol1andprofile1/Table,5.pdf . live .
15. http://www.clarecoco.ie/planning/publications/draft-clare-county-development-plan-2017-2023-volume-3b-shannon-municipal-district-written-statement-and-maps-21924.pdf Draft Clare County Development Plan 2017–2023 Volume 3b Shannon municipal district written statement and maps December 2015
16. Dublin Marine Institute 1998: Studies of Irish Rivers and Lakes: Moriarty, Christopher – Table 10.1.
17. Web site: Google Maps . 2014-10-12 . 2014-12-18 . https://web.archive.org/web/20141218074153/https://www.google.com/maps/d/kml?mid=zg_XReEZJPKI.kph8gVk8VSec&ie=UTF8&t=m&vpsrc=0&oe=UTF8&msa=0&output=kml . live .
18. Web site: THE GSI GROUNDWATER NEWSLETTER – Page 9 . 2014-10-12 . 2016-03-04 . https://web.archive.org/web/20160304024523/https://www.gsi.ie/NR/rdonlyres/0F4C3C51-EF38-46AA-8D7F-2229E9663EF0/0/No30.pdf . dead .