Langmann-Stausee, reservoir in Austria

The Langmann-Stausee is a small reservoir near Sankt Martin am Wöllmißberg in Austria, formed by a dam that holds back the Teigitsch river. The water is fed by several mountain streams and flows through a pressure tunnel more than five kilometers long to the nearby Arnstein power station.

The Langmann dam was built between 1922 and 1925 by STEWEAG under architect Fritz Haas. It served as a daily storage reservoir for the Arnstein power station, completed in the same period as the oldest part of the Teigitsch group and then Austria's largest power plant. Materials reached the site via several kilometres of narrow-gauge field railway and an inclined lift from Gaisfeld station on the Graz-Köflacher railway.

The reservoir takes its name from the Langmann dam, built by the STEWEAG utility between 1922 and 1925 under architect Fritz Haas. On the left bank stands a monument to Anton Rintelen, former provincial governor of Styria and STEWEAG administrative president. Fishing is popular here, while swimming and boating are banned, unlike at the nearby Hirzmann reservoir.

The dam is about 85 meters long and 26 meters tall, with a walkway across its crest that offers views of the water and surrounding landscape. The terrain is flat and suitable for walking, though swimming and boating are prohibited, and since there are no facilities at the water's edge, bring your own refreshments and snacks.

The dam's crest was an engineering feat for its time, constructed under challenging conditions using hand carts and narrow gauge rail tracks. The entire water volume can be discharged in less than five hours if needed, demonstrating how the system was engineered to precisely manage power generation for the region.