river and loch (lake), Scotland. The River Tummel rises on Rannoch Moor near the southern border of the Highland council area and drains via Loch Laidon through the heavily glaciated east-west valley containing the ribbon lakes (Lochs Rannoch and Tummel, in the Perth and Kinross council area) until it joins the River Tay just northwest of Pitlochry. The extensive Tummel-Garry Hydro-Electric Scheme, comprising 10 main power stations, is a major feature of the Tummel River basin. Loch Tummel is a popular scenic spot, as are the Falls of Tummel near the confluence of the Rivers Tummel and Garry.