BARROW, a river of south-eastern Ireland. It rises in the Slieve Bloom mountains, and flows eastward and then almost due south, to form the estuary known as Waterford harbour. Includ ing the I 2m. of the estuary, the length of its valley is rather more than i oo miles. The total area of drainage to Waterford harbour (including the basin of the Suir) is 3,5oosq.m., and covers the whole of the county of Kilkenny, with parts of Waterford, Cork and Limerick, Tipperary, Carlow, King's and Queen's counties.