An international border is invisible underground, but the location of a pumping well can make a difference to the communities on either side. Intensive groundwater abstraction close to a border has greater potential to affect neighbouring users than comparable pumping farther away. Yet cooperation often focuses on which aquifers countries share, with less attention to where water is actually being withdrawn.
That distinction is at the heart of Why Groundwater Use Location Matters in Transboundary Aquifers, a policy brief published in October 2026 by the United Nations University Institute for Water, Environment and Health (UNU-INWEH). Its central argument is straightforward: sharing an aquifer does not necessarily mean sharing the same groundwater problem.