Patterns in transboundary aquifer governance: comparative analysis of eight case studies from the perspective of efficacy.

We performed a comparative analysis of eight case studies worldwide from the perspective of transboundary aquifer governance efficacy. First, we mapped variation in institutional design, applying institutional design criteria in four dimensions linked to The OECD Principles on Water Governance. We then identified explanatory factors: (1) physical variables, including aquifer size and hydrogeological characteristics; (2) watershed variables, including groundwater exploitation capacity and water transfer infrastructure; and (3) political factors, including international donor support. We found that transboundary aquifer governance efficacy is closely linked to problem structure and less attributable to institutional design in the presence of specific contextual variables. [ABSTRACT FROM AUTHOR]