Regular observations of the seepage regime of the earth dams of the Dneprodzerzhinsk hydrostation made it possible to conduct a constant analysis of the condition of the dams. Main stabilization of the seepage regime of the earth dams occurred during the first year after filling the reservoir. It was detected by the method of temperature measurements that an increase of the seepage heads on the right-bank abutment is not related to bypass seepage of the reservoir. An increase of the seepage heads in the summer (seasonal fluctuations) is explained by the effect of the temperature regime and it does not affect the reliability of the structure. The low position of the seepage line can be considered a favorable factor.