Transboundary groundwater governance in the Guarani Aquifer System: reflections from a survey of global and regional experts

To understand transboundary groundwater governance in the South American Guarani Aquifer System, we surveyed global and regional experts about the region’s groundwater quantity and quality, ownership and rights, and regulation and administration. Respondents (1) perceived groundwater quality and withdrawal as under-regulated, and relevant information and data as inadequate; (2) suggested that contamination and overdrafting remain mostly incipient and localized along international borders; and (3) viewed groundwater as a shared resource administered by the state for the public, rather than as private property. Respondents suggested that while there is progress towards implementing a formal transboundary aquifer agreement, local-to-national-scale governance is important.