A procedure to design stable channel reach system is proposed in this paper. This procedure employs the concept of optimization, which requires the definition of an objective function and the consideration of governing system equations that describe the flow hydraulics involved, the bed erosion and mobility in the channel, and system requirements that set the stable design criteria. The advantages of this procedure are compared with the advantages of conventional procedures. Four case studies involving four reach types (i.e., simple reach, multi-reach system in series, multi-reach system in parallel, and dentritic-reach system) are presented representing various drainage projects in Arizona, and a conceptual problem. The case studies are presented to show and demonstrate the capability of the optimization modeling approach to channel design. The resulting non-linear optimization problems derived from the four case studies are solved using GAMS-MINOS, an optimizer code developed by Brooke et al (1996). The optimization problem involving design of stable channel reach system considers economic performance as the objective function. Copyright ASCE 2004.