Lake Davos (German: Davosersee) is a small natural lake at Davos, Switzerland . Its surface area is 0.59 km² and the maximum depth is 54 m. Fed by Sources of the Rhine , Flüelabach and Totalpbach, among other mountain creeks, the lake is used as a hydropower reservoir; its water no longer flows to the river Landwasser but is channeled into the river Landquart at Klosters .