Optimal Treated Wastewater Allocation Among Stakeholders Based on an Agent-based Approach

Using unconventional water resources, such as treated wastewater (TWW), is an excellent alternative to meet excess water demands. Policymakers should consider optimal and equitable allocation of TWW to relieve conflicts among stakeholders. In the current research, an agent-based model (ABM) is integrated with a multi-objective optimization method (MOM) to fairly distribute water among different beneficiaries in Tehran Province, Iran. In ABM there are two groups of agents: water users and managers. Water users seek to minimize water shortages, and water managers are responsible for allocating water to the users fairly. Managers also assess different bankruptcy scenarios (BSs) for allocating TWW to each stakeholder, and the most agreeable scenario is selected. The Conditional Value-at-Risk (CVaR)-based objective functions are used to assess the risk of uncertainties under different confidence levels. Then, to prioritize the Pareto-optimal solutions, a novel multi-criteria decision-making (MCDM) method, named R-method, is utilized. Results show that considering stakeholders' objectives and interactions can lead to finding a more equitable solution. Interactions among beneficiaries can diminish water shortages in the study area through an investment by the industrial sector in the agricultural sector to improve the efficiency of agricultural activities.