Population growth coupled with increased urban and agricultural water use have exacerbated water shortages worldwide. Conflicts among water users frequently arise over scarce water. The application of conflict resolution methods has the potential to resolve such conflicts. Bankruptcy games is a branch of game theory applicable to problems dealing with conflict resolution. This study addresses water allocation to urban-industrial, agricultural, and environmental water uses downstream of the Zarrineh-roud dam, Iran, which diverts water from the Zarrineh-roud River, an important tributary to Lake Urmia. Lake Urmia has been severely stressed by reduction of its water inputs. Water allocation is posed in this study as a bankruptcy game in which the allocation to stakeholders is optimized with proportional (P), adjusted proportional, constrained equal award (CEA), and constrained equal losses methods. The CEA was chosen as the best allocation method based on performance criteria and the Bankruptcy Allocation Sustainability Index. Monthly, real-time, water allocation rule curves were calculated with genetic programming.