The objective of this study is the modeling of the atomization and dispersion of an irrigation water jet, from the nozzle outlet to the region of full development of the spray. The use of an Eulerian model, developed for high Reynolds and Weber numbers fluid flow, provides a continuous description of the process. In this model, the conservation équations are written for a two phase mixture. A transport equation for the volume density of the interface represents fragmentation/coalescence mechanisms and gives mean liquid fragments size. The numerical results obtained by this model were compared to experimental measurements of mean velocity, turbulent kinetic energy, liquid volume fraction and Sauter Mean Diameter. The model overestimates the decrease of the longitudinal velocity on the axis, but successfully predicts the volume fraction and mean droplet size profiles.