The Burn Dennet is a medium-sized (5-20 meters width) spate river.
Rising on the northern flanks of the main Sperrins ridge, the river drops northwards through Donemana, swinging west through native woodland and pasture before meandering across broad flats to reach the River Foyle upstream of the walled city of Londonderry.
Sea trout peak June to August, with grilse best fished for in July and August and salmon in August and September.
