A calculation was carried out and a numerical modeling of the foundation of an hydromeliorative dam was carried out during its operation in a pressure-variable mode, using the MIDAS GTX NX software package, by building a computational model based on the real engineering-geological state of the object, when horizontal stresses (kN/m2) depending on the variable water level in the upstream and downstream, a mathematical model of the process is obtained from the named factors and the degree of influence of each of them is revealed.