While high urban vegetable demand has driven unprecedented intensification of small private irrigation in peri-urban Kenya, absence of appropriate local governance mechanisms has necessitated interventions by concerned state agencies. Based on Ostrom’s design principles for sustainable commons, this paper evaluates the robustness of the irrigation management regime emanating from involuntary self-governance among peri-urban farmers. Findings show that since conflicts were fueled by water scarcity peaks corresponding with market price peaks, the interventions overemphasized facilitating water sharing among users. With conflicting users viewed as the problem by the agency, their experiences with the resource system, existing social structures, and resource use dynamics causing conflicts were largely ignored in the change process. Consequently, narrowly focused use rules that failed to properly define important resource parameters resulted. Further, user drawing rights have no significant input requirement, monitoring of water resource condition and sanctioning of deviant behavior are overlooked due to a lack of sufficient social capital and commitment to the collective establishment. Although inherent conflicts signify high economic valuation of water access by users, the lack of local ownership of the transition process made the policy interventions fail to produce rules that can guarantee sustainable irrigation development in an environment characterized by intensive irrigation and agrochemicals application, and growing domestic and industrial water demand. Therefore, recognizing water as a commercial input, recognizing conflicting users and their experiences as an essential solution, and integrating them in a participatory manner in subsequent institutional change is deemed necessary for effective governance in the post-conflict setup.