The paper focusses on water distribution systems (WDSs) of a general configuration, whose operation profile is decided by solving a sequential linear program (SLP). The paper introduces linearization procedure for a general network. The necessary SLP mathematical form for a general WDS is also derived. Cost function and all the constraints for the WDS optimization are elaborated. To validate the approach, the derived procedure is applied to a toy example and to a large segment of a WDS from a city in Spain. The results are compared with the operation policy obtained using hysteresis control and substantial operational costs reduction possibilities are demonstrated while respecting all WDS constraints.