Achieving United Nations Sustainable Development Goal 6 through sustainable groundwater use in the Water-Energy-Food Nexus perspective in arid areas

We present a groundwater-based strategy for achieving UN Sustainable Development Goal (SDG) 6 Water and Sanitation in arid, data-scarce regions through a Water-Energy-Food (WEF) Nexus modelling approach. A density-dependent groundwater flow model, built using the FREEWAT-Q3 platform and SEAWAT code, evaluated the sustainability of groundwater use for both drinking and irrigation in Wadi Naghamish area (Egypt), in a region challenged by chronic water scarcity and socio-economic vulnerability. The implemented model simulated groundwater dynamics, seawater intrusion, and groundwater salinity changes under various conditions, including climate change scenarios up to a 30% reduction in aquifer rainfall recharge. Results showed that a groundwater withdrawal scheme using two wells at 24 L/s total capacity remained sustainable, with minimal impact on aquifer balance and salinity (TDS changes less than 1 g/L). Groundwater pumping combined with partial desalination was found to be far more energy-efficient and climate-friendly than full seawater desalination. Groundwater-based systems produced 226 kg/day of CO₂ emissions using diesel and only 42 kg/day with renewables—compared to 1301 kg/day and 241 kg/day, respectively, for seawater desalination. The proposed irrigation system could transform local agriculture by irrigating about 45 hectares for two cropping seasons a year, boosting food production and societal resilience. The proposed WEF Nexus approach ensures that water, energy, and food production systems are harmonized, avoiding sectoral trade-offs. Additionally, we demonstrated that the integration of traditional water practices like jessour may enhance sustainability. Beyond SDG 6, our results support the achievement of SDGs 1, 2, 3, and 13. The Wadi Naghamish case exemplifies how groundwater Nexus-based planning can guide low-carbon, sustainable water solutions—though enhanced data collection is essential to validate and to scale such planning.