Zervreilasee is a reservoir located south-west of Vals in the canton of Graubünden, Switzerland .

The lake has a surface area of 1.61 km² and an elevation of 1,862 m. The maximum depth is 140 m. The dam is 151 m high and was completed in 1957. The village of Zervreila was flooded after the construction of the dam. A 150-metre-long bridge (Canalbrücke) crosses the southern bay of the lake.