Allt Graad (or River Glass) is a river in Easter Ross

Easter Ross

Easter Ross is a loosely defined area in the east of Ross, Highland, Scotland.The name is used in the constituency name Caithness, Sutherland and Easter Ross, which is the name of both a British House of Commons constituency and a Scottish Parliament constituency...

, Highland

Highland (council area)

Highland is a council area in the Scottish Highlands and is the largest local government area in both Scotland and the United Kingdom as a whole. It shares borders with the council areas of Moray, Aberdeenshire, Perth and Kinross, and Argyll and Bute. Their councils, and those of Angus and...

, Scotland. It is named on Ordnance Survey maps variously as Allt Graad and River Glass. It has also been known as the "Allt Grande", and the archaic Anglicization, "Aultgraad".

As of 2011, a hydro-electric scheme is under construction on the Allt Graad. This run-of-the-river

Run-of-the-river hydroelectricity

Run-of-the-river hydroelectricity is a type of hydroelectric generation whereby a considerably smaller water storage called pondage or none is used to supply a power station. Run-of-the-river power plants are classified as with or without pondage...

 scheme is on the lower catchment of the river, next to the Black Rock Gorge. It will be operated by RWE Npower, and have a capacity of 3.5MW.

Course

The Allt Graad flows 9 km (5½ miles) from Loch Glass through Glen Glass past Evanton

Evanton

Evanton is a large village in Easter Ross, in the Highland Council Area of Scotland. It lies between the river Sgitheach and the Allt Graad, is north of the city of Inverness, some south-west of Alness, and north-east of Dingwall. The village has a dozen or so streets, the main one being...

 into the Cromarty Firth

Cromarty Firth

The Cromarty Firth of Cromarty') is an arm of the North Sea in Scotland. It is the middle of the three sea lochs at the head of the Moray Firth: to the north lies the Dornoch Firth, and to the south the Beauly Firth....

. Between Glen Glass and Evanton it flows through the Black Rock Gorge

Black Rock Gorge

Black Rock Gorge is a deep and narrow cleft in Old Red Sandstone conglomerate through which the Allt Graad flows in Easter Ross, Scotland...

, associated in local tradition with the Lady of Balconie. It meets the sea about a mile from the mouth of the River Sgitheach

River Sgitheach

River Sgitheach also known as Skiach or Skiack, is a river in Ross and Cromarty, Scotland...

.