Unterer Bockhartsee, reservoir in Sankt Johann im Pongau, Salzburg, Austria

Unterer Bockhartsee is a high-altitude reservoir in the Austrian Alps at about 1,870 meters elevation, situated in a mountain valley surrounded by steep rocky slopes. The water is held back by a dam approximately 40 meters wide and over 5 meters high, storing more than 700,000 cubic meters of water.

The lake was created in the early 20th century by engineers for mining operations and hydroelectric power, with the dam serving the mining activities of that era. Over the decades, the dam was raised multiple times, most recently in 2007 by about 8 meters, to increase water storage capacity for power generation.

The name Pochkarsee arose during the medieval peak of gold mining in the region, then shifted over time to Pockhart, Bockhardt and finally Bockhartsee. The lake belongs to the former Bockhartrevier, where gold was mined until the mid-20th century.

The lake is accessible via hiking trails from nearby settlements, with marked paths leading through the mountain landscape. Visitors should bring weatherproof clothing and sturdy footwear, as conditions at this elevation can change quickly and the terrain is rocky.

The dam's crest is 39.6 m long and its maximum height 5.5 m after the 2007 works, which raised it by a further eight metres. The reservoir was enlarged to hold 704,000 cubic metres more water, and the original intake was replaced by a pressure tunnel. The name Bockhartsee descends from Pochkarsee, used in the medieval heyday of gold mining here.