The River Poddle is a river in Dublin, Ireland, a pool of which gave the city its English language name. Boosted by a channel made by the Abbey of St. Thomas à Becket, taking water from the far larger River Dodder, the Poddle was the main source of drinking water for the city for more than 500 years, from the 1240s. The Poddle, which flows wholly within the traditional County Dublin, is one of around a hundred members of the River Liffey system, and one of over 135 watercourses in the county; it has just one significant natural tributary, the Commons Water from Crumlin.