Gigerwaldsee

Gigerwaldsee
	Gigerwaldsee in the Calfeisental
Location:	Canton of St. Gallen
Tributaries:	Tamina , Tellerbach , Hoch Bach
Drain:	Tamina
Larger places on the shore:	St. Martin
	Canton of St. Gallen , Switzerland
Coordinates	747 367 / 197 712 coordinates: 46 ° 54 '51 " N , 9 ° 22' 24" O ; CH1903: 747 367 / 197 712
	Data on the structure
Lock type:	Arch dam
Construction time:	1976
Height of the barrier structure :	147 m
Height above the river bed :	135 m
Building volume:	460 000 m³
Crown length:	430 m
Operator:	KW Sarganserland AG, Pfäfers
	Data on the reservoir
Altitude (at congestion destination )	1335 m above sea level M.
Water surface	71 ha
Reservoir length	3 km
Storage space	33 400 000 m³
Total storage space :	35 600 000 m³
Catchment area	52.06 km²
Design flood :	180 m³ / s
	Detailed map

The Gigerwaldsee is located in the Calfeisental in the area of the political community Pfäfers in the canton of St. Gallen .

Reservoir

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

The Gigerwaldsee is part of the pumped storage plant built by Kraftwerke Sarganserland (KSL) from 1971 to 1977 , 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.

Technical specifications

Gigerwald dam

Double curved arch dam
Maximum height above foundation	147 m
Crown length	430 m
Minimal wall thickness at the crown	7 m
Maximum wall thickness at the foot	22 m
Height of the wall crown	1337 m above sea level M.
Concrete cubature	446,000 m³

Hydraulic equipment

	Mapragg power plant	Sarelli power plant
Turbines	3 vertical axis Francis turbines	2 vertical axis Francis turbines
Turbine power	93 300 kW each	45,000 kW each
rotational speed	600 rpm	750 rpm
Swallowing ability	25 m³ / s each	15 m³ / s each
pump	3 vertical axis two-stage pumps
Pump performance	53,000 kW each
Delivery rate	8.6 to 11.9 m³ / s each