Speicher Durlaßboden, reservoir in Austria

The Speicher Durlaßboden is a large mountain reservoir in the Alps near Gerlos, held back by an earth dam and situated about 1,400 meters (4,600 feet) above sea level. The basin reaches depths of up to 55 meters (180 feet) and offers a walking path around it used by hikers, cyclists, and mountain bikers, with several mountain huts along the route.

The Oberstufe above the Gerlos power plant was planned during the Second World War but built between 1963 and 1967 as part of the Gerlos power plant group, operated by Zillertaler Verbund AG. Its barrier is an 83 m high, 450 m long earthfill dam with a central sealing core, and a grout curtain reaching 60 m deep seals the subsoil. Water from the Salzach headwaters is diverted into the reservoir, which holds up to 50.7 million m³ at a target level of 1405 m; the Funsingau plant below has a peak output of 200 MW.

The reservoir lies on the Gerlos pass road, which marks the state border between Tyrol and Salzburg; the water surface itself is split between the municipalities of Gerlos and Krimml. The dam is an earth-fill embankment with a central sealing core, 83 m high and 450 m long, and its name comes from the Durlaßboden alpine pasture on the Salzburg side.

Access to the reservoir is straightforward, with walking paths circling the water that suit families and cyclists. The best time for swimming and water sports is summer, when the water warms to about 21 degrees Celsius (70 degrees Fahrenheit).

The reservoir hosts one of Austria's highest sailing and windsurfing schools, where visitors can also rent kayaks, pedal boats, and paddleboards. The water is also popular with divers, especially in autumn, when clarity allows visibility down to 20 meters (65 feet).