The results of data analysis from complex field studies of vertical deformations of the rock base near-contact layer and full settling Boguchanskaya HPP concrete dam sections in order to determine the state of contact of the foot of the concrete dam with the rock base are presented. The purpose of the study is to control the state of the contact of the concrete dam foot with the foundation based on the analysis of a set of field studies of the vertical deformations of the near-contact zone of the foundation of the concrete dam sections and the total draft of the sections of the concrete dam to justify the stability of the concrete dam sections. In order to control the vertical deformations of the near-contact zone of the rock foundation, string control and measuring equipment (displacement sensors PLPS-10) was installed. The total draft of the concrete dam sections is measured by means of ceiling marks installed in the grout gallery. Analysis of the field data on total drafts of concrete dam sections and vertical deformations of the near-contact section of the rock foundation showed that the contact joint between the foot of the concrete dam sections and the foundation is in vertical compression. The results of the analysis of the available data of complex studies of vertical deformations of the near-contact layer of the rock foundation and the total draft of the concrete dam sections made it possible to substantiate the stability of the concrete dam sections.