The dam's construction necessitated the complete relocation of several local villages, including Stary Żywiec and Zarzecze.
The reservoir is known locally as Jezioro Żywieckie and is the second-largest artificial lake in the region.
The structure operates as part of the Sola Cascade, a system of three dams designed to control the flow of the Soła River.
During periods of extreme drought, remnants of the flooded villages can occasionally be detected on the lake floor via sonar.
The dam serves both as a hydroelectric facility and a critical flood control barrier for the town of Żywiec and the lower Vistula basin.
Zapora Tresna is a 39-meter high earth-fill dam located in the Żywiec Beskids, forming the expansive Lake Żywiec. Completed in 1966, the structure regulates the Soła River and serves as a vital component of the Tresna Pumped-Storage Power Station. The dam spans approximately 310 meters in length and holds back over 95 million cubic meters of water. It features a controlled spillway system necessary for managing seasonal floodwaters. The surrounding reservoir, Jezioro Żywieckie, covers 10 square kilometers and is used for flood protection and hydroelectric power generation. The area is a hub for water sports, including sailing, windsurfing, and recreational fishing. Pedestrians can cross the dam top, providing a vantage point overlooking the water and the distant peaks of the Beskid Mały mountain range.
The center of the dam walkway looking toward the Beskid Mały mountain range at sunset.
Walk the full length of the dam for panoramic views of the water on one side and the river valley on the other.
Bring binoculars if visiting for birdwatching, as the reservoir attracts numerous migratory waterbird species.
Check local wind conditions before planning water activities, as the valley can experience sudden gusts.
Do not attempt to swim near the dam wall or the power station intake structures, as strong currents and underwater machinery pose severe safety risks.
