Abstract A groundwater geochemistry study was carried out on 24 samples collected from different springs and wells situated in a plateau area at an elevation of 200–300 m in the Mehedinţi County, southwestern Romania. The study was motivated by the fact that springs have represented the only source of potable water in the region, only recently completed by tens of metres-deep well drillings. Spring distributions and geological data reveal the presence of a multilayered system situated in the Lower Quaternary deposits. The mean δ 18 O and δ D values of groundwater, −9.8 and −67.8‰, respectively, reflect the yearly weighted mean of the isotopic composition of precipitation, demonstrating locally derived recharge. The Piper ternary diagrams indicate that the dominant hydrochemical type is HCO 3 − –Ca 2+ –Mg 2+ with transition towards higher SO 4 2− and Mg 2+ contents to the deeper aquifer. The anions vary from HCO 3 − with transition to no dominant type and with Cl − contents higher for the shallower aquifer. The sequence of abundance of cations is generally Ca 2+ > Mg 2+ > K + > Na + and for anions: HCO 3 − > SO 4 2− > Cl − > NO 3 − > F − . Radiocarbon dating of dissolved inorganic carbon indicates a subrecent recharge of the aquifers. The vertical and lateral variations in groundwater chemistry may vary, and are influenced by lateral lithologic variation of the Quaternary clastic deposits. This is an unpredictable quality factor when taking the decision for the drinking water drill locations.

Water access, sanitation, and security remain key foci of international aid and development. However, the increasing interconnectedness of hydrologic and social systems can cause water initiatives to have unexpected and cascading effects across geographic scales. This presents new challenges for geoscientists working in water development, as distant and complex socioeconomic and environmental relationships, or “telecouplings,” may significantly influence the outcomes and sustainability of development projects. We explore these emerging concepts through a case study in Ethiopia, which receives over half of its annual budget from foreign development assistance and is currently experiencing rapid population growth and environmental change. Using examples from the literature, we identify water development aid initiatives in rural and urban settings and at local and national scales. We then situate these within the telecoupling framework to reveal underlying social-hydrological relationships. Our results indicate that water development is linking Ethiopia’s hydrology with geographically distant communities and markets and creating new and often unexpected flows of people, material, and capital. These are resulting in cascading impacts and cross-scale feedbacks among urbanization, geopolitics, and the water-food-energy nexus in East Africa. We conclude with a discussion of the strengths, limitations, and potential of the telecoupling framework for geoscientists and development practitioners.