The Stausee Solis ("Solis reservoir") is a reservoir on the Albula river, located between Alvaschein , Stierva and Tiefencastel , in the canton of Graubünden.

Its surface area is 17.75 ha (43.9 acres). It was built in 1986 by the Electric Power Company of Zurich (ewz). A dam of 61 m (200 ft) height and a crown length of 75 m (246 ft) holds back the water in the lake. The water in the reservoir is used for energy production further downstream in the power plants Sils and Rothenbrunnen. This dam is used as daily storage.