Due to recent increasing water demand, planning and projecting of water resources has resulted in increased costs. Therefore, it is important to obtain optimum results in project planning. In this study, dimensioning of open channels used especially for irrigation purposes has been studied using a particle swarm optimization algorithm to investigate optimum base width, channel height, and slope angles. The results are summarized in graphs and tables. In the study, it was found that the optimum slope angle varied between 0.2(0) (boolean OR) 0.45(0) . Furthermore, it was found that increasing the slope angle significantly increased costs. Finally, the increase in flow increases costs but the rate of increase diminishes.