Dublin's municipal authorities used to list around fifty watercourses, and the County authorities more again. The undisputed leader in the Dublin region is the Liffey, followed by major tributary, the Dodder, and by the Tolka. While others carry a fair volume of water, notably the Wad River system, the Mayne, the Santry and the Poddle, some of the other "rivers" are really just streams and the majority are culverted for some or even all of their lengths. In the greater Dublin Strategic Drainage Study, seven of the lesser rivers were considered, with the Tolka added later; the Dodder and Liffey were not included.
The Liffey (An Life in Irish) is a river in Ireland, which flows through the centre of Dublin. Its major tributaries include the River Dodder, the River Poddle and the River Camac. Dividing the Northside of Dublin from the Southside, the Liffey is spanned by numerous bridges mostly open to vehicular traffic. Notable are the West-Link Bridge on theM50 motorway, the Sean Heuston Bridge, the O'Connell Bridge, and the Millennium and Ha'penny foot bridges.
Crossings further upriver include the Liffey Bridge at Celbridge, "The Bridge at 16" (a 19th century pedestrian suspension bridge at the K Club), and the Leinster Aqueduct - which carries the Grand Canal over the Liffey at Caragh.
The River Camac (sometimes spelled Cammock) is a river in Dublin. The Camac rises to the west of the city and flows through Clondalkin, Inchicore and Kilmainham before entering the Liffey just downstream from Heuston Station. The Camac is sourced from three streams from the Dublin Mountains and Co. Kildare and join together in Corcaigh Park, just south of Clondalkin village. The River Dodder (An Dothra in Irish) rises on the northern slopes of Kippure in the Wicklow Mountains. From there it flows for some 20 km through Tallaght and the Dublin suburbs ofRathfarnham, Templeogue, Milltown, Clonskeagh, Donnybrook, and Ballsbridge before entering the Liffey at Ringsend. The River Poddle is linked with the River Dodder as it flows through Tallaght - this link used to help with Dublin City's water supply. To catch sea trout on this river it is best fished in September at night when the river is in spate. There is a weir just above the bridge at Ballsbridge and the river becomes tidal roughly where the bridge at Lansdowne Road crosses it. The Dodder and the River Tolka are Dublin's second largest rivers, after the River Liffey. The Naniken River is a minor river on the north side of Dublin city, Ireland, one of more than forty watercourses monitored by Dublin City Council. The Naniken rises in the vicinity of Santry Lane, between Santry and Ballymun, passes through Beaumont and Artane, under the Malahide Road near the Artane Roundabout, then under Harmonstown and into Raheny, where it once formed the boundary of the Church of Ireland glebe (rectory lands), passing under Howth Road and forming a feature of St. Anne's Park, where it supplies the Old Pond, and enters the western half of the "lagoon" behindNorth Bull Island. The line of the Naniken from its mouth marks the boundary of the civil parish of Raheny with that of Clontarf, and the beginning of the Raheny portion of the Bull Island. There is a drainage link between the Naniken and the Santry River to reduce the flow from the river's upper reaches, and to deal with flooding or overflow situations. The River Poddle, one of the fifty or so rivers of Dublin, rises in Fettercairn, Tallaght, flows through Templeogue and eventually into the Liffey near Wood Quay. Formerly they met at a place known as the Dubh Linn (black pool), a place now the site of the Coach house and Castle Gardens of Dublin Castle - this may have been the origin of Dublins name. The river formed an early supply of water to the city, as the Liffey was tidal where they met. By the 13th century the water supply was inadequate and a deal was made in 1244 with the Priory of St. Thomas to divert water from the Dodder to the Poddle to increase the water flow; this connection still exists. In 1592, Red Hugh O'Donnell and Art O'Neill escaped from Dublin Castle via a drain into the Poddle, which runs under the Castle from Ship Street gate to the Chapel Royal and the Undercroft. The Poddle was later used to provide a water defence for the south wall of the castle. Nowadays much of the lower course of the Poddle is in a culvert under city streets but it has caused flooding on occasions over the years, in the late 1800s, for example, leading to changes within St. Patrick's Cathedral. The confluence of the Poddle with the Liffey is visible at low tide, at Usher's Quay. Santry River (Irish: Abhainn Seantrabh) (formerly Skillings Glas) is a fairly small river on the north side of Dublin city, one of the forty or so watercourses monitored by Dublin City Council. The Santry rises at an elevation of c. 80m, in the semi-rural areas of Harristown and Dubber in the part of County Dublin now administered by Fingal County Council, near the village of St. Margaret's and Dublin Airport. One branch can be found at the end of a small lane in the former Harristown Demesne, now cut off by new road development. The river then flows along to the south of Dublin Airport (from which some tributary streams enter it), near the new Dublin Bus Harristown depot. It passes for most of its course out in the open, flowing through Sillogue Public Golf Course and then more of Ballymun, then Santry, where it forms a major feature of the Santry Demesne, with small lakes within the public park. In Coolock, the river forms a central feature, and features ornamental ponds, running past the Stardust Memorial Park, and through the grounds of Cadbury's, where there is an EPA monitoring station. It then enters Raheny just below Tonlegee Road, flowing alongside Edenmore lands, past St. Joseph's Hospital, then through the village centre, along the grounds of Manor House School, and then, with two areas of culverting, at the beginning and end of the Bettyglen Estate, reaches the sea, where its mouth forms part of the eastern "lagoon" behind North Bull Island, and the flow enters Sutton Creek. The dotted line on the above sketch is an artificial link made by Dublin Corporation between the Santry River and the Naniken River, to reduce the flow of the latter and to allow handling of any flooding in either watercourse. As part of the management of the river, the Santry is one of the third tier rivers being numerically mapped within the Greater Dublin Strategic Drainage Study, with floodplain hydraulics computed (the other rivers being the Carrickmines, Deansgrange, Poddle, Camac, Finglas and Mayne, along with one of the two second tier waterways, the Tolka). The Santry has been noted for pollution incidents over the years, with industrial effluent and building material the most common causes (some of the latter once caused the main pond by the Stardust Memorial to be drained and reformed). The River Tolka (Irish: An Tulcha) is a river which flows through Dublin, Ireland. It rises near Dunshaughlin, Co. Meath, bypassing Dunboyne, Mulhuddart, Blanchardstown, Finglas, then through the north Dublin districts of Glasnevin, Drumcondra (beside Tolka Park) and Ballybough, before entering Dublin Bay at East Wall. The Tolka is, with the River Dodder, one of Dublin's main rivers, after the River Liffey. In November 2000, flooding of the Tolka caused extensive damage to residential areas along its banks. Since then, much work has been done to strengthen its flood defences. The Tolka is connected to the nearby Royal Canal by what is known as the Cemetery Drain, so-called as it runs beneath Glasnevin Cemetery before joining the Tolka in the Botanic Gardens.