This paper presents a hybrid model that calculates the heads, the discharges in pipes, the head losses in pipes (caused by discharges and valves) and the booster heads in hydraulic networks. The steady state is calculated considering the hydraulic network without valves and boosters. The extended period simulation is calculated considering the presence of valves and/or boosters to solve over pressure and/or under pressure problems respectively. The hybrid model uses a genetic algorithm to minimize the dissipated hydraulic power sum in the whole hydraulic network for all calculation time steps of the extended period simulation (objective function) by setting optimal valve openings. It was studied how it affects the behavior of a hydraulic network. A real hydraulic network that had over pressure and under pressure problems was analyzed. It was necessary to install boosters and valves to solve the pressure problems. The results show that when valves were installed without planning its openings, the total head losses increased from 5.9% to 13.6%, while the total head losses in the same hydraulic network increased 2.7% when planning the installed valves openings. It's concluded that the dissipated power minimization was an effective way to optimize the studied hydraulic network operations by minimizing the head losses increases caused by the installed valves.