River Poddle in Templeogue flowing downstream towards the River Liffey
|Origin||Cookstown, Tallaght, County Dublin|
|Mouth||Discharges into River Liffey at Wellington Quay (Map)|
|River system||River Liffey|
The River Poddle (Irish: An Poitéal), is one of the best known of the more than a hundred watercourses of Dublin. It is the source of the name "Dublin", the city being named after a pool that was once on its course. It rises in the Cookstown area in northern Tallaght, and flows into the River Liffey in the city centre.
The Poddle begins as the Tymon River in the Cookstown area northwest of Tallaght village, near the site of Fettercairn House, and flows east, through Tymon North, and northeast, forming the northern border of Templeogue, towards Greenhills. Additional ponds were added to its course when Tymon Park was formed in the 1980s and 1990s. The river flows from Greenhills into Kimmage, where it used to receive an artificial stream from Templeogue. This stream consisted of water from the River Dodder extracted at Balrothery Weir.
City Watercourse 
The Poddle's modest volume was increased for over 700 years by the significant input of water diverted from the River Dodder at the great weir at Balrothery north of Firhouse, and carried by the three kilometre first section of the City Watercourse. The ancient watercourse was, without explanation, disrupted in recent times by development allowed by the County Council, and it no longer operates.
The Tongue 
The river is split at "The Tongue" at Mount Argus, with one third of the flow forming the second section of the City Watercourse, heading for Crumlin Road and Dolphin's Barn, and two thirds continuing in the original river bed. In the 1990s, changes were made in the Kimmage area, including the addition of a large fountain to the river.
Lower course 
The two flows later recombine and pass under much of the south city centre in a culvert. The final stages of the river's flow are complex, with waters separating and joining. Linked flows include the Tenter Water, and the river is joined by the Commons Water. The present main course is itself a diversion of the original course, which lay further east.
Nowadays, much of the lower course of the Poddle is in a large brick tunnel under the city streets and Dublin Castle, and while access is restricted, it is walkable.
The confluence of the Poddle and the Liffey is visible at low tide through a grated opening in the Liffey walls at Wellington Quay (picture below).
Dubh Linn and the origins of "Dublin" 
A large, dark pool once existed at the confluence of the Rivers Poddle and Liffey; this pool was described in Irish as dubh linn, which means black pool. The city name, Dublin, is an anglicisation of this Irish phrase, dubh linn. This historic pool existed under the present site of the Coach House and Castle Gardens of Dublin Castle.
The Poddle was known colloquially as the river Salach, or dirty river in Irish. A variation of this name is used in the old children's song The River Saile (or Weile Weile Waila), famously performed by The Dubliners.
In 1592, Red Hugh O'Donnell and Art O'Neill escaped from Dublin Castle through 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.
For centuries the Poddle, progressively culverted, caused regular flooding and constant dampness in many buildings in the Blackpitts to St. Patrick's Street areas, including St. Patrick's Cathedral. For much of this time, a special public body, the Poddle Commission, operated, working to manage this, and with the power to raise a special tax to support its work. During a major reconstruction of the cathedral in the nineteenth century, the graves of Dean Jonathan Swift and Stella were moved to their present location, due to the problem of the Poddle.
Water supply 
The river provided an early source of water for the city as the Liffey was tidal within the city area, and undrinkable, and the other major south-side water, the Camac, was too far from the main settlement, while the Stayne River was too small. By the 13th century the water supply was inadequate and a deal was made, in 1244/1245, with the Priory of St. Thomas to divert water from the Dodder at the weir at Balrothery near Firhouse to the Poddle, to provide the greater part of the water flow. As mentioned, this connection was allowed to dry out in the late 20th century, and only a tiny part still carries water, though ample evidence of the watercourse can be seen: the sluices and channel on the north side of the Firhouse weir still stand.
See also 
Primary source 
- Dublin, Ireland: Sweeney, Clair; The Rivers of Dublin; Dublin Corporation, 1991
- A history of Dublins' water supply
- Details of stones found in Poddle Culvert in 1901
- Details of finds near Poddle culvert
- Dublin Castle History - mention of Poddle
- Tymon Regional Park - mentions where Poddle rises
- Pictures and short video of the Abbey stream, River Poddle, in Blackpitts, Dublin
- Urban Tales program on RTE Tracks the history of the Poddle