Engineering optimization has been used in a wide spread of fields that attracts the attention of designers. One of the engineering optimization problems is the optimization of the open canals which are mostly used as water transfer structures in water resources. Design of open canal structures is a complex task due to the fact that the designer has to select suitable dimensions of sections within certain range of values and such selection should satisfy the flow requirements to convey a specific discharge in the canal. In this study, dimensions of cross sections of open canals are optimized by using bees algorithm in order to investigate performance of this algorithm in the optimum design of open canal problems. Four design problems are considered to optimize and results obtained from these problems are compared to results obtained from previous studies.