In the laboratory of Hydraulics and Hydraulic Construction of the Faculty of Engineering of L'Aquila, a physical model was made for the study of steady-state, gradually varied motion flow in open channel networks. For this study, a calculus algorithm has been used proposed by [1] which gives, in the case of slow water flow into gradually declined channels, in the direction of motion, the volumes and water levels respectively, in all the nodes and sides of the network.