Lac de Tseuzier, reservoir in Switzerland

Lac de Tseuzier is an artificial reservoir in the municipalities of Ayent and Icogne in Valais, Switzerland. Its water is held by two structures completed in 1957: the 156-metre Zeuzier arch dam and the 20-metre Proz-Riond embankment dam. The reservoir holds 51 million cubic metres of water and covers 0.85 square kilometres.

The lake was formed by two dams completed in 1957: the 156-metre Zeuzier arch dam and the 20-metre Proz-Riond embankment dam. Probe drilling at the Zeuzier dam revealed larger wall movements than expected, which led to a lowering of the water level and contributed to delays in the Rawil Pass motorway project; the project was later abandoned and made obsolete by the Lötschberg Base Tunnel.

The lake is used by both locals and visitors who value the quiet and mountain surroundings. The place connects traditional alpine farming with modern water management, showing how communities have lived and worked in these mountains for generations.

The lake is easily accessible from spring to autumn with free parking at the dam and good walking trails around the water. Comfortable shoes, water, and snacks are recommended, and in bad weather or winter the roads and paths can become difficult or unsafe to navigate.

The dam is named Zeuzier, not Rawyl, and the reservoir holds 51 million m³ behind a 156 m arch dam and a 20 m embankment dam, both completed in 1957. Probe drilling during the 1950s caused larger wall movements than expected, which lowered the water level and helped delay a planned Rawil Pass motorway until the project was abandoned.