The dam of the reservoir Pîrcovaci, located on the Bahlui River is a homogeneous earth dam with a maximum height of 24.0 m., The foundation ground was sealed with a concrete screen on a length of 390 m and an average depth of 10.0 m. In order to control the infiltration regime, a drainage network was built, consisting of a collector drain along the downstream side of the dam and 5 transverse drains in the downstream prism, that discharge into the longitudinal drain. For tracking the evolution of seepage from the dam and the embankments, 28 piezometers and 4 infiltration discharge and measurement sections are used. Variations of the water level in the reservoir, the precipitation, and the temperatures are the external stresses that influenced the dam Pîrcovaci had as a first effect on the variation of the infiltration levels in the piezometers and the seepage flows. This paper presents a brief description of the dam and aspects regarding the behavior monitoring in time, during the years 1997-2021, and it focuses on the characteristic elements of the theoretical infiltration curve in the dam, the hydro isohypses for the dam drawn with SURFER program, using the maximum hydrostatic levels in the piezometers measured in the year 2021.