The article provides the information on a promising technology for trenchless repair named Swagelining, which supposes pulling into the old pipeline the new polymer with its preliminary thermo-mechanical compression and further straightening. The coauthors present the results of the calculations determining the thickness of the polyethylene pipes after compression and straightening in the old pipeline depending on the initial diameter in case of different ratio of the diameter to the wall thickness (SDR) and the dynamics of the changes in hydraulic performance after repair work on the pipeline using the method Swagelining. The concept of the energy saving potential is formed in addition to a no-dig repair for pressure piping systems, water supply, and its magnitude. On the basis of the research results, the authors formulate the principles of the energy efficiency potential after the implementation of the trenchless technology of drawing the old pipeline with new polymer pipes with their preliminary thermo-mechanical compression and subsequent area enlargement. The technology Swagelining is described and the authors develop a mathematical model that illustrates the behavior of the pipeline in the process of shrink operations. Such parameters are analyzed as changing the diameter of the pipeline at thermo-mechanical compression, the hydraulic parameters of the new (polymer) and old (steel) pipelines, energy savings on one-meter length of the pipeline. The calculated values of the electric power economy on the whole length of the pipeline repair section with a corresponding flow of transported waters.The characteristics and capabilities of the technology of trenchless renovation Swagelining allows achieving simultaneously the effect of resource saving (eliminationof the defects and, as a consequence, of water leakage) and energy saving (reduction in the water transportation cost).A numerical example of the old steel pipeline renovation shows the calculated data, which proves the efficiency of the considered technology. The calculation results can be used as base material for designers when selecting the final decision of the alternative at reconstruction of dilapidated pipelines by Swagelining using a wide range of polymer pipes with the corresponding value of the SDR.