The state of Zacatecas, located in the Mexican Republic, is a primarily agricultural region that has experienced severe droughts in recent years, affecting local farming and highlighting the need for efficient water use. In response, the adoption and optimization of irrigation systems have become essential for supporting agriculture and minimizing water scarcity. This article presents a novel methodology for redistributing flow rates in open-channel irrigation systems by adjusting the diameters of the outlet orifices. The proposed methodology leverages principles from fluid mechanics, particularly internal and viscous flow, to accurately calculate the necessary orifice sizes that allow for a uniform and effective distribution of water across the entire irrigation network. The methodology is applied to a case study involving an open network with 14 outlets, where the goal was to achieve a homogeneous water flow to meet crop irrigation needs while conserving water. Using equations for head loss and flow rate determination, along with iterative calculations for orifice sizing, the study demonstrates how water flow redistribution can be effectively implemented in irrigation systems with fixed pipe diameters. Additionally, the methodology offers flexibility to adapt to different network configurations and variable pressures, making it applicable to a wide range of agricultural irrigation systems. The findings of this study are relevant to researchers and practitioners aiming to enhance water management in agricultural areas, particularly in regions prone to water scarcity. This approach also has potential for broader applications in hydraulic systems where uniform flow distribution is desired. Keywords: Irrigation System, Open network system, Applied fluid mechanics.