This paper examines the dynamism and robustness of two irrigation systems of the Kok River system within the Mekong River basin in northern Thailand in the context of changing governance mechanisms and evolution of technological and market forces. It analyzes both temporal and spatial dynamism of the irrigation systems. The temporal dynamism was analyzed over three phases: before intervention, initial operation, and long-term. The before intervention phase analysis examined the effect of various attributes of users on starting an irrigation system, whereas the initial operation phase inquiry included the process of development of rules and level of autonomy in developing the users' own rules over time. The long-term phase analysis focused on external factors affecting the sustainment of these irrigation systems. Spatial dynamism was examined across upstream and downstream systems and within different locations of the system. The analysis was centered on linkages and relationships between five entities: resource, resource users, public infrastructure, public infrastructure providers, and external disturbances. Both systems were still robust, owing to the sustainment of local customs and the role of local leaders still vital, albeit in different forms. The group efforts, their self-governing capabilities, and local institutions, including the changed role of leaders in dealing with external forces, have played an important role in maintaining the robustness of these systems.