Raising of the Mauvoisin Dam

Construction of the 237 m high Mauvoisin arch dam in Switzerland started in 1951 and the reservoir was filled completely for the first time in 1958. The purpose for raising the dam was to shift energy production from summer to winter, when it is most needed. Heightening required adjustments of the spillway and the tailrace tunnel of a run-of-river plant located upstream reservoir. Construction time extended over a period of three years. The performance of the heightened dam was monitored by an elaborate system of plumb lines, temperature and pressure sensors and found to be entirely satisfactory.