Gigerwaldsee, Glarus

The reservoir can be reached via Bad Ragaz through the Tamina valley. The last larger village is Vättis. From there, a mountain road and, on summer weekends, a post bus route lead to the dam wall, which is located about 400 meters higher and was completed in 1976. Along the southern shore of the lake, a narrow road leads through several tunnels to the former Walser settlement of St. Martin. The road is closed in winter due to avalanche danger. Lake Gigerwald is the largest lake that lies exclusively on St. Gallen territory.

Lake Gigerwald is part of the pumped storage plant built from 1971 to 1977 by Kraftwerke Sarganserland (KSL), a partner plant of the Canton of St. Gallen and Axpo AG. It uses water from the upper Weisstannental and its side valleys, the Calfeisental and the Tamina Valley and generates an average of 460 million kilowatt hours of electricity annually.