Abstract
The hydroelectric plant Râul Mare Retezat is the second largest plant on the inland rivers in Romania. The main adduction gallery has a length of 18km and four water supplies along it. The construction of an additional compensation tank, connected to the protective device, the surge tank, can additionally supply the hydroelectric plant with water, reducing the head losses and resulting in much more efficient utilization of water volumes. Consequently, electricity production can be increased, compared to the initial situation, by up to 6%.