River Tay
The River Tay emerges from Loch Tay at Kenmore, and flows from there to Perth which, in historical times, was its lowest bridging point. Below Perth the river becomes tidal and enters the Firth of Tay. The largest city on the river, Dundee, lies on the north bank of the Firth. On reaching the North Sea, the River Tay has flowed from west to east across central Scotland.
Eye Water
The stretch of the river from Ayton onward previously had some pollution problems as a quantity of sewage effluent from the village of Ayton and Eymouth contaminated the Water. However, in 2005 Scottish Water completed work which collected the sewage from the villages and pumped it directly to the sewage treatment works at Eyemouth on the coast. At Ayton the Eye Water swings NNE for the final five km leg to its estuary. It runs under the A1 road in a wooded gorge and then receives its largest tributary on its northern bank, the Ale Water which rises on Coldingham Moor 10 km to the NW. The Eye Water enters Eyemouth where it flows on the east side of the harbour, with a stone built quay keeping it separate and forming the river's west bank before the Water eventually enters the harbour lower down near the life boat station.