The object of research. Long-term operation of sewer tunnels in difficult engineering and geological conditions creates the danger of violating their structural safety. A long-term study of the changes’ dynamics in the technical state of the tunnels made it possible to establish the patterns of intense anthropogenic and dynamic influences on this process. Method. The developed discrete and continuous diagnostic models of the defects’ development in the tunnels’ structures make it possible to identify potentially hazardous areas subject to the manifestation of critical failures and methods of their localization. On the basis of numerical modeling, the boundaries of defect-free joint operation of the system “source of impact – geo-mass - sewer tunnel” have been determined. Results. With increasing external anthropogenic and dynamic impacts, modeling zones of urban areas with potentially dangerous sections of underground sewage facilities is the basis for the development of regulatory documents on monitoring methods and safe development geotechnical infrastructure.