This paper presents a non-elastic matrix model to calculate hydraulic networks, based on a method created by Nahavandi and Catanzaro (Journal of Hydraulics Division, 99(HY1), pp.47-63, 1973). It is a method that calculates the discharges and pressure heads in hydraulic networks for the steady state, for the extended period and for the transient state. This method has advantages concerning the Cross method, because the latter does not allow the calculation of transient situations such as the settings of valves, the starting and stopping of boosters, the branch ruptures, etc. The applicability of the method created by Nahavandi and Catanzaro was enhanced, because the programming and input data to consider the presence of valves, reservoirs or boosters in the hydraulic network were developed. Furthermore, the mathematical formulation and programming to calculate the extended period and transient state were also developed. The matrix method is working well, because the model was applied to calculate some hydraulic networks used as examples and the values calculated by the model are similar to the ones obtained from the technical literature.