Heiterwanger See is directly connected to the neighboring Plansee by a narrow, artificial channel built in the 20th century.
The lake reaches a maximum depth of approximately 60 meters.
During the Roman era, the lake was a transit point on the Via Claudia Augusta, a major trade route connecting Italy to the Danube.
Water temperatures in the lake rarely exceed 19°C, even during the peak of summer, due to its glacial origins.
The lake functions as a natural reservoir that feeds into the Plansee power station for hydroelectric energy production.
Heiterwanger See is a turquoise glacial lake in the Tyrol region, connected to the larger Plansee via a short channel. The lake is situated at an elevation of 976 meters, surrounded by the Lechtal Alps and the Ammergau Alps. It is known for its high water quality, often reaching drinking water standards. The area is a popular hub for stand-up paddling (SUP), swimming, and rowing due to the calm, wind-protected water surface. A flat, forested trail encircles the lake, catering to both walkers and mountain bikers. The lake serves as a starting point for boat tours that navigate the connected water system between Heiterwanger See and Plansee. Underwater visibility in the lake can reach up to 10 meters, making it a destination for freshwater diving. Motorized watercraft are strictly prohibited to maintain the ecological balance of the alpine environment.
The small wooden bridge spanning the channel between Heiterwanger See and Plansee.
Rent a boat at the lake restaurant to access the channel connecting to Plansee for a more expansive view of the surrounding peaks.
Bring water shoes, as the lake shoreline consists of rocky pebbles rather than sand.
Check local wind conditions in the morning, as the lake is calmest before midday mountain thermals begin.
Attempting to swim across to the Plansee side without a support vessel, as boat traffic in the connecting channel can be unpredictable.
Boat tours operate only from late spring through early autumn; the lake trail may be icy or inaccessible during deep winter.
Use designated waste disposal areas; leave no trace to protect the alpine water quality.
