Shown here are all the major rivers and tributaries of Ireland with their lengths (in kilometres and miles). Starting with the Ulster rivers, and going in a clockwise direction, the rivers (and tributaries) are listed in regard to their entry into the different seas: the Irish Sea, the Celtic Sea and the Atlantic Ocean. Also shown are two tables. Table 1 shows the longest rivers in Ireland with their lengths (in kilometres and miles), the counties they flow through, and their catchment areas (in square kilometres). Table 2 shows the largest rivers in Ireland (by mean flow) in cubic metres per second.

The longest river in Ireland is the River Shannon, at . The river develops into three lakes along its course, Lough Allen, Lough Ree and Lough Derg. Of these, Lough Derg is the largest. The Shannon enters the Atlantic Ocean at the Shannon Estuary. Other major rivers include the River Liffey, River Lee, River Swilly, River Foyle, River Lagan, River Erne, River Blackwater, River Nore, River Suir, River Barrow (The Three Sisters), River Bann, River Slaney, River Boyne, River Moy and River Corrib.

Longest Irish Rivers (with Basin areas) Lengths obtained from the Ordnance Survey of Ireland: Rivers and their Catchment Basins 1958 (Table of Reference), and for the rivers Bann and Erne – Notes on River Basins by Robert A. Williams River Counties Length Basin Area 1 River Shannon (including estuary and flow through lakes)a Cavan, Leitrim, Roscommon, Longford, Westmeath, Galway, Offaly, Tipperary, Clare, Limerick, Kerry 360 km (224 mi) 16,800 km2Comprehensive study of Riverine Inputs Details of hydrometric stations, sampling stations Page 17, Table 2 2 River Barrowb Laois, Kildare, Kilkenny, Carlow, Wexford, Waterford 192 km (119 mi) 3,067 km2 3 River Suirb Tipperary, Waterford, Kilkenny, Wexford 184 km (114.5 mi) 3,610 km2 4 River Blackwater (Munster) Kerry, Cork, Waterford 168 km (104.5 mi) 3,324 km2 5 River Bann (including flow through L. Neagh)c Down, Armagh, Antrim, Londonderry 159 km (99 mi) 5,808 km2Ordnance Survey of Ireland: Rivers and their Catchment Basins 1958 (Table of Reference) 6 River Noreb Tipperary, Laois, Kilkenny 140 km (87 mi) 2,530 km2 7 River Suck (Shannon) Roscommon, Galway 133 km (83 mi) 1,600 km2Dublin Marine Institute 1998: Studies of Irish Rivers and Lakes: Moriarty, Christopher 8 River Liffey Wicklow, Kildare, Dublin 132 km (82 mi) 1,256 km2 9 River Erne Cavan, Fermanagh, Donegal 129 km (80 mi) 4,372 km2 10 River Foyle (including Rivers Mourne, Strule & Camowen) Tyrone, Londonderry, Donegal 129 km (80 mi) 2,925 km2 11 River Slaney Wicklow, Carlow, Wexford 117 km (73 mi) 1,762 km2 12 River Boyne Kildare, Offaly, Meath, Louth 113 km (70 mi) 2,695 km2 13 River Moy Sligo, Mayo 101 km (62.5 mi) 2,086 km2 14 River Clare (Corrib)d Mayo, Roscommon, Galway 93 km (58 mi)1,108 km2 15 River Blackwater (Ulster) (Bann) c Tyrone, Monaghan, Armagh 92 km (57 mi) 1,507 km2 16t River Inny (Shannon) Cavan, Longford, Westmeath 89 km (55.5 mi) 1,254 km2 16t River Lee Cork 89 km (55.5 mi) 1,253 km2 18 River Lagan Down, Antrim 86 km (53.5 mi) 565 km2 19 River Brosna (Shannon) Westmeath, Offaly 79 km (49 mi) 1,248 km2 20 River Laune (includes Lough Leane and River Flesk) Kerry 76 km (47.25 mi) 829 km2 21 River Feale (Shannon) Cork, Limerick, Kerry 74 km (46 mi) 1,170 km2 22 River Bandon Cork 72 km (45 mi) 608 km2 23 River Blackwater (Boyne) Cavan, Meath 68 km (42.5 mi) 733 km2 24 River Annalee (Erne) Monaghan, Cavan 66.8 km (41.75 mi) 522 km2 25 River Bride (M. Blackwater) Cork, Waterford 64 km (40 mi) 419 km2 26 Boyle River (including Lung River) (Shannon) Mayo, Sligo, Roscommon 64 km (40 mi) 725 km2 27 River Deel (Shannon) Cork, Limerick 63.2 km (39.5 mi) 481 km2 28 River Robe (Corrib)d Mayo 62.8 km (39.25 mi) 320 km2 29 River Finn (County Donegal) (Foyle) Donegal, Tyrone 62.8 km (39.25 mi) 505 km2 30 River Maigue (Shannon) Cork, Limerick 62 km (38.75 mi) 1,000 km2 31 Fane River Monaghan, Armagh, Louth 61.2 km (38.25 mi) 350 km2 32 Ballisodare River Sligo 60.8 km (38 mi) 650 km2 33 River Dee (Louth) Cavan, Meath, Louth 60.4 km (37.75 mi) 392 km2 34 River Fergus (Shannon) Clare 58.4 km (36.5 mi) 1,043 km2 35 Little Brosna River (Shannon) Offaly, Tipperary 57.6 km (36 mi) 662 km2 36 Mulkear River (including Bilboa River) (Shannon) Tipperary, Limerick 55.9 km (34.75 mi) 650 km2 37 River Glyde (Co. Louth) Cavan, Meath, Louth 55.9 km (34.75 mi) 348 km2 TABLE 1

a The length of the River Shannon from the Shannon Pot to Limerick City is with a basin area of 11,700 km2. The River Shannon's overall length (to Loop Head), using the Owenmore River (County Cavan) as source, is ,Shannon River Basin: Furthest sourceShannon River Basin#Furthest sources 11 km (7 mi) longer than the Shannon Pot source. The River Shannon's overall length (to Loop Head), using the Boyle River's furthest source, is ,Boyle River (Ireland) making the Boyle-Shannon river the longest natural stream flow (source to sea) in Ireland, 31.6 km (19.5 mi) longer than the Shannon Pot source. The River Shannon is a traditional freshwater river for just about 45% of its total length. Excluding the tidal estuary from its total length of , if one also excludes the lakes (L. Derg , L. Ree , L. Allen 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.

b The total basin area of the Three Sisters (Barrow, Nore and Suir) is 9,207 km2.

c The traditional length given for the River Bann is 80 miles (129 km) which is the combined total length of Upper and Lower Bann rivers and doesn't include Lough Neagh. The total length of the Ulster Blackwater from its source to the sea via L. Neagh and the Lower Bann is 186.3 km (115.75 mi),Ulster BlackwaterRiver Blackwater, Northern Ireland surpassed, in Ireland, only by the Shannon and Barrow rivers. This is the longest stream flow (source to sea) in Ulster.

d The total basin area of the 6 km River Corrib is 3,138 km2 The total length of the River Robe's journey from its source near Ballyhaunis to Galway Bay (via Lough Mask, Cong canal and river, Lough Corrib and River Corrib) is .River Robe This is the longest stream flow (source to sea) within the Corrib Basin.

Largest Irish Rivers (by flow) River (River Basin) Mean Discharge (m3/s) 1 River Shannona 209 (300) 2 River Corrib 105.5 3 River Bannb 92 (102.5) 4 River Foyle 90 5 River Blackwater (Munster) 87.5 6 River Erne 85 7 River Suirc 76 8 River Moy 63 9 River Barrowc 46.5 10 River Laune 43 11 River Norec 42 12 River Lee 40 13 River Slaney 39 14 River Boyne 38.5 15 River Cong (Corrib) 37.6 16 River FealeLong-term effects of hydropower installations and associated river regulation on River Shannon eel populations: mitigation and management (Shannon) 34.6 17 River Fergus (Shannon) 25.7 18 River ClareRoyal Irish Academy, Atlas of Ireland (Royal Irish Academy, Dublin, 1979) Hydrology P. 23 – Rivers: Mean Discharge (Corrib) 22.9 19 River Suck (Shannon) 22.2 20 River Avoca 22 21 River Bandon 21.5 22 River Mourne (Foyle) 21.1 23 River Blackwater (Ulster) (Bann) 19.7 24 River Ballisodare 18.25 25 River Inny (Shannon) 18.4 26 River Liffey 17 27 River Derg (Foyle) 16.2 28 River Maigue (Shannon) 15.6 29 River Main (Bann) 15.4 30 River Blackwater (Boyne) (Boyne) 15.08 31 Aille River (Connacht) (Corrib) 15.0 32 Owenmore River (County Mayo) 14.7 33 Boyle River (Shannon) 13.57 34 River Deel (Shannon) 12.56 35 Mulkear River (Shannon) 12.55 TABLE 2

a The River Shannon's 209 m3/s is to Limerick City (Catchment area: 11,700 km2). If the discharges from all of the rivers and streams into the Shannon Estuary (including the rivers Feale 34.6m3/s, Maigue 15.6m3/s, Fergus 25.7m3/s, and Deel 7.4m3/s) are added to the discharge at Limerick giving a total catchment of 16,865 km2, the total discharge of the River Shannon at its mouth at Loop Head reaches 300 m3/s

b The River Bann's 92 m3/s is to Movanagher Gauging station (Basin area 5209.8 km2). The 102.5 m3/s is based on the total basin area of 5808 km2 .

c The Three Sisters (Barrow, Nore & Suir) total flow into Waterford Harbour is 154 m3/s and the combined flow of the Barrow and Nore rivers is 86 m3/s before joining the river Suir near Waterford City.

Rivers in Ulster With length in miles (and km)

River Crana River Lennon (Leannan) River Foyle (total) – that portion named "Foyle" forms the border between the Republic of Ireland and Northern Ireland Burn Dale (also known as the River Deele) – rises in and flows through the east of County Donegal – River Finn (Foyle tributary) – rises and flows mainly through County Donegal, Republic of Ireland River Reelan River Mourne River Derg Mournebeg River Owenkillew River Glenelly River Owenreagh River River Strule Camowen River Drumragh River Fairy Water Drumquin River Routing Burn Owenreagh River Cloghfin River Glenmornan River River Faughan River Roe River Bann River Blackwater River Callan Oona Water River Torrent River Tall River Blackwater (Northern) River Main Six Mile Water Ballinderry River Moyola River Clady River Knockoneil River Grillagh River Agivey River Cusher River Clady River Altmore River Cromore Burn Devlin River Cronaniv Burn River Dun River Bush River Erne (See Atlantic rivers) River Lagan River Farset Blackstaff River River Quoile Clanrye (Newry) River

Rivers in the Republic of Ireland, flowing into the Irish Sea With length in miles (and km)

Castletown River Cully Water Kilcurry River River Fane River Glyde River Dee, County Louth River Boyne River Owenroe (Moynalty) River Blackwater, Kildare and Meath River Blackwater, Cavan and Meath Moynalty River Athboy River River Turry 3.2 miles (5 km) Stonestown River Dale River Kinnegad River Yellow River River Nanny River Tolka River Liffey Kings River Morell River River Rye Lyreen River River Camac River Poddle River Dodder Owendoher River River Dargle River Vartry River Avoca (Ovoca) River Avonmore River Avonbeg Aughrim River River Slaney Derreen River River Derry River Bann (Wexford)

Rivers in the Republic of Ireland, flowing into the Celtic Sea With length in miles (and km)

River Barrow Philipstown River Figile River River Slate River Triogue Finnery River Tully Stream River Greese Burren River River Nore River Erkina River Goul River Dinan Kings River River Suir River Drish River Clodiagh Aherlow River River Ara River Anner John's River River Tar River Duag River Colligan River Mahon River Blackwater, Cork River Owentaraglen River Allow River Funshion River Finisk River Awbeg River Dalua River Bride River Womanagh Owenacurra River Glashaboy River River Lee River Sullane Shournagh River River Bride River Bandon River Ilen Argideen River River Owenabue

Rivers in the Republic of Ireland, flowing into the Atlantic Ocean With length in miles (and km)

Roughty River (flowing into Kenmare Bay) at Kenmare River Laune River Flesk Gweestin River Caragh River River Inny (Kerry) Cummeragh River River Ferta River Carrowbeg River Maine Brown Flesk River Feale River Galey Allaghaun River Smerlagh (Smaorlagh) River Shanow River River Shannon Owenmore River (County Cavan) Arigna River Feorish River River Brosna Clodiagh River Tullamore River Silver River Bunowen River Little Brosna River River Camcor Ballyfinboy River Nenagh River Ollatrim River River Inny River Tang River Suck River Shiven Boyle River (Total) Boyle River Lung River Breedoge River Camlin River Mulkear River Bilboa River River Deel River Maigue River Fergus River Corrib Cregg River (via Lough Corrib) River Clare (via Lough Corrib) Grange River Abbert River River Black Aille River (Connacht) Baelanabrack River River Robe (via Loughs Mask and Corrib) River Clarin Clady River Cromore Burn Cronaniv Burn Kilcolgan River Dooyertha River Kinvarra River River Doonbeg River Inagh