Monitoring systems for water distribution and sewerage networks constitutes an indispensable condition for smooth operational management of existing communal infrastructure. The question of an effective use of resources and means to supervise, regulate and control water supply networks requires special care already in the planning stage and also during the implementation process of maintenance equipment. To meet the above demand telemetry and data system to monitor the performance of water mains has been developed making use of GSM/GPRS data transfer technology. One of the fundamental problems of building the system is how to supply energy to the distributed control and measurement devices. A possible solution to these problems could be, as proposed in this paper, a wireless energy supply system using the measuring medium, i.e. the flowing water for energy transport. To this end, a construction of a mini-hydrodynamic generator, i.e. a device transforming the kinetic energy of water into electrical energy using carbon polymers reinforced with carbon fibers has been made, in which the flow of the operational medium is the working environment.