Ampervreilsee

Ampervreilsee is a reservoir above the village of Vals in the Graubünden canton of Switzerland. That is the name used in our system, but the lake is officially and in most guidebooks called Zervreilasee (also Zervreilastausee or Zerfreilasee). Ampervreila is a variant that shows up on maps, tied to the old hamlet of Zervreila that now lies underwater. The lake sits in the Valsertal at 1,862 m above sea level.

What is Zervreilasee?

It is an artificial lake created by the Zervreila dam, completed in 1957. The arch dam stands 151 m high with a crest roughly 504 m long. The reservoir holds about 100 million m³ of water, covers around 1.6 km² and reaches a depth of up to 140 m. Its water feeds the power plants of Kraftwerke Zervreila, part of a hydro scheme built during the 1950s.

What lies beneath the surface?

When the basin filled, the small settlement of Zervreila (locally also spelled Zerfreila) at the head of the valley was flooded. The lake's name is now its main reminder. Above the water rises the peak Zervreilahorn, which makes a recognisable backdrop for photos from the shore.

How do you get there?

The lake lies in the upper part of the valley, above Vals village. A mountain road leads from Vals to the parking area by the dam. In winter a walking route with views of the lake and Zervreilahorn operates here, and a gondola from Vals brings you to its start. Check current road conditions and transport timetables before you go, since both depend on the season at this altitude.

What can you do at the lake?

• Walk by the dam and along the crest. A good short visit, with views of the dam wall and the water.
• Vals – Zervreilasee loop. The summer version is about 16.7 km with nearly 1,000 m of ascent, topping out at 1,995 m, according to Bergwelten. Allow around 5 h 45 min.
• Winter Panoramaweg. About 5.4 km with 240 m of climbing, roughly 2 hours on foot.
• Kronenwanderung, stage 6. The route leaves Zervreila, follows the lake and then the Valser Rhein valley up to Läntahütte at 2,090 m. It is about 10.4 km and takes around 3 hours.

When should you visit?

Summer and early autumn give the best hiking conditions, with trails free of snow. In winter the valley suits walks on prepared paths, but expect plenty of snow and short days. At nearly 1,900 m the weather changes fast, so pack a warm layer even on a clear day.

Where to stay and eat?

The nearest base is Vals, known for its thermal baths, with lodging and restaurants. The lake is a short trip from the village, so it pairs well with a longer stay in the valley.

Frequently asked questions

Are Ampervreilsee and Zervreilasee the same lake? Yes. Zervreilasee is the official name used in guides, while Ampervreilsee is a map variant. Both refer to the reservoir above Vals.

Is the lake natural? No. It is a reservoir that formed after the Zervreila dam was completed in 1957, flooding the old settlement.

How tall is the dam? It is 151 m high, and the crest is about 504 m long.

Is it the same as Guraletschsee? No. Guraletschsee is a different lake near Vals. The reservoir described here lies deeper in the valley, below the Zervreilahorn peak.