The development of main pipeline networks for water transportation involves widespread and heavy usage of modern measurement and computing equipment, and remote control systems. The magnitude of the hydraulic resistance coefficient of pipeline sections has a significant impact on water motion in pipelines. Over an extended period of pipeline operation, the hydraulic resistance coefficients of sections undergo changes, specifically, they increase due to the processes of hydrate formation on the inner surface of pipelines. Therefore, it is of great practical importance to involve mathematical methods for identifying hydraulic resistance coefficients for operational monitoring of the condition of pipeline network sections, which makes it possible to identify suspicious areas where hydrate formation processes have actively begun to occur, which significantly affects the loss of fluid energy, as a result of which it is necessary to artificially increase the energy of liquid at pumping (compressor) stations. We consider an approach to identifying the hydraulic resistance coefficient of a linear segment within a water supply network. The considered identification problem is reduced to a class of finite-dimensional optimization problems, for the solution of which we propose to use effective first-order finite-dimensional numerical optimization methods.