Coalition-Informed Allocation Strategies During Participatory Regional Groundwater Management in Texas

Decentralized and participatory groundwater management is becoming more common in many parts of the world and is the preferred approach of aquifer management in the State of Texas.  However, groundwater planning under multi-stakeholder settings will likely lead to formation of coalitions or sub-groups, where in stakeholders with common interests are likely to come together in an effort to obtain benefits that are likely to be larger for the group as a whole than what they would have obtained by negotiating individually.  However, the eventual success of any such coalitions critically hinges on how well they able to divide the joint pay-off (benefit) that have accrued by acting as a single group with unified interests.  The literature on n-person game theory provides insights with regards to how stakeholders can divide pay-offs using economic principles of rationality and efficiency.  There are several metrics such as the Shapley value that can be used to determine the optimal pay-off for each member of the coalition.  More importantly, N-person game theory can be used to identify which stakeholders benefit by forming coalitions and are therefore likely to do so.  The approach therefore provide valuable insights with regards to the dynamics of participatory decision making process.  A decision support system that integrates regional flow models with optimization tools and n-person game theoretic concepts was developed to identify optimal and rational allocations of groundwater resources.  The functionality of the developed model will be illustrated using a case study from South Texas.