The lengths of the three rivers of the Three Sisters are the Barrow - 192 km (119 mi), the Suir - 185 km (115 mi) and the Nore - 140 km (87 mi).
The combined catchment area of the Three Sisters is 9,207 km2, made up of the Suir's (3,610 km2), the Barrow's (3,067 km2) and the Nore's (2,530 km2).[1]
The combined long term average flow rate of the Three Sisters into Waterford Harbour is 157 m3/s, almost half of which is made up of the Suir's (76.9 m3/s), followed by the Nore's (42.9 m3/s) and the Barrow's (37.4 m3/s).[1][dead link]
The Barrow Bridge crosses two of the Three Sisters, the Nore and the Barrow. They then join the River Suir just downstream of the bridge. This place is known in Irish as Cumar na dTrí Uisce, "the confluence of the three waters". The Nore joins the Barrow some four kilometres north of New Ross and the combined waters of the three sisters that can be seen from Cheekpoint. The combined waters of all three sisters are then visible all the way down the estuary from Cheekpoint on.
The first, the gentle Shure that making way
By sweet Clonmell, adorns rich Waterford;
The next, the stubborne Newre, whose waters gray,
By faire Kilkenny and Rosseponte boord,
The third, the goodly Barow, which doth hoorde
Great heaps of Salmons in his deepe bosome:
All which long sundred, doe at last accord
To ioyne in one, ere to the sea they come,
So flowing all from one, all one at last become.
Excerpt from Edmund Spencer's Irish rivers . 1552-1559
References
^ abSouth Eastern River Basin District Management System. Page 38 "Archived copy"(PDF). Archived from the original(PDF) on 3 March 2016. Retrieved 2 March 2015.{{cite web}}: CS1 maint: archived copy as title (link)