Ausserferrera / Innerferrera

Ausserferrera (1,321 m/4,334ft) lies in a wider part of Val Rerrera. From here the road runs through the Ragn da Ferrera defile. To the right are the Ferrera turbine house (185,000 kW), hewn from the rock, and a compensation basin (230,000 cu. m/8million cu. ft) for the reservoir in the Valle di Lei. Then, opposite the mouth of the Val d'Emet or Val Niemet, the village of Innerferrera (Romansch Canicül or Canlantgil, 1,480 m/4,856ft) is reached. The road next crosses the Averser Rhein, runs through a tunnel (200 m/656ft) and then another grandiose defile (natural rock arch), with a waterfall at the mouth of the Val Starlera on the left. After another tunnel (500 m/1,641ft) it comes to the new bridge (lower down, the old bridge) over the Reno di Lei. This river issues from the Italian Valle di Lei, in which a dam was built in 1957-61 as a joint Swiss-Italian enterprise (Valle di Lei-Hinterrhein hydroelectric scheme). 100 m/328ft beyond the bridge the road goes through another tunnel (250 m/820ft), and 1.3km/1mi farther on a road branches off on the right to the dam. This runs uphill, with two sharp bends, and in 2.5km/2mi reaches a tunnel 1km/ 0.6mi long (traffic lights; closed in winter), at the far end of which are the Swiss-Italian frontier, the Swiss customs (on right) and beyond this the dam (parking). The dam rises to a height of 138 m/453ft above the foundations and is 635 m/2,083ft long at the top. The artificial lake formed by the dam, the Lago di Lei (alt. 1,931m/6,336ft, capacity 197million cu.m/6,956million cu.ft), lies in Italian territory. The water is carried down under pressure in a tunnel 6.9km/4mi long to the Ferrera turbine house.