Zillergründl Dam, Arch dam in Zillertal Alps, Austria

The Zillergründl Dam is a variable-radius arch dam on the Ziller River in the upper Ziller Valley of Tyrol, 16 km east of Mayrhofen. Its crest sits at 1,850.7 m above sea level; the structure is 186 m tall and 502 m long, 6 m wide at the crest and 36 m at the base, holding back a reservoir of 89,500,000 m3.

Work began on this arch dam in 1981 and finished in 1986 as part of a broader hydroelectric project in the Ziller region. The development was built to meet growing energy needs in the area.

The Zillergrund valley sustains traditional Alpine herding, with farmers bringing livestock to high pastures each summer as families have done for centuries. This seasonal practice shapes how the landscape looks and feels throughout the year, connecting people to the mountains around them.

The site is reachable by a toll road from parking areas in the region, and bus services connect to the main access points. Weather at high elevation can change quickly, so sturdy footwear and layered clothing are helpful for anyone walking around the area.

The Zillergründl reservoir is refilled at night, when demand and prices are low: the Häusling station pumps water 8 km west from the Stillupp Reservoir in the neighbouring valley back up to 1,850 m. Generation then resumes in peak-demand hours, so the same water is reused.