The River Kent begins above the reservoir in the heights of Bleathwaite Crag. It collects beneath Kentmere Common in the reservoir which was built in 1848 to control the flow of water to the lower pastures. Lingmell Gill also feeds into the reservoir. Beside the reservoir sits a disused quarry and a cottage formerly used for maintenance of the river. The river opens out into a transitory lake called Kentmere Tarn just south of the confluence with Hall Gill. The lake has at times in the past completely disappeared into marshland and in 1840 it was purposely drained to provide reclaimed farm land, but in the past 100 years the "mere" has reappeared again. It is currently 1 mile in length. An archaeological excavation there uncovered an 'extended' log boat dated to c. 1300 AD (D.M. Wilson, A Medieval Boat from Kentmere, Westmorland, in "Medieval Archaeology" (1966) 10. 81–88). Other tributaries within the valley include Ullstone Gill, Nunnery Beck, Nuttera Beck, Park Beck and Hall Beck. A waterfall known as Force Jump is situated just north of the village, and there are two bridges at the Staveley end of the valley. The first is called Barley Bridge and includes a dramatic weir. The second straddles the Kent further up the valley and is known as Scrogg's Bridge.