This paper establishes a complex highly nonlinear model of a submersible pump station with three pump aggregates, in the water factory NAISSUS in Niš, using the theory of bond graphs. To verify the model accuracy there are performed several simulations in the software package Dymola. To reduce power consumption of the pumps and to eliminate the need for classic switching tables, herein, we propose the fuzzy-PI controller. The obtained experimental results confirms the effectiveness of the proposed control logic and the power required for the pump station is significantly reduced