Lac de Pérolles, a lake formed by Maigrauge Dam, is a reservoir on the Saane/Sarine river at Fribourg, in western Switzerland. Its surface area is 0.35 square kilometres (35 ha; 86 acres). The dam was built in 1872, and its height was increased by 2.5 metres (8.2 ft) in 1910. The watershed (or catchment) is 1,250 square kilometres (480 sq mi). The Maigrauge Dam has a gated spillway.