A new optimized procedure for circular WasteWater sustainability: Coastal cities supporting agricultural rural communities

This proposal introduces a novel methodology that addresses the increasing irrigation demands driven by climate change and urban growth. Traditionally water-scarce areas are now facing severe water deficits, while wastewater volumes from treatment plants, often discharged into the sea, contribute to pollution. The proposed hybrid system strategy innovatively reallocates 33 hm 3 of water annually to agricultural communities, employing a zero-discharge approach to prevent marine pollution. Evaluated from energetic, environmental, and social perspectives, this methodology shows a remarkable cost-benefit ratio exceeding 12, showing its feasibility. It features technical indicators for optimizing water distribution and regulatory components, applied effectively to 28,424 ha of farmland. This strategy meets 24.1 % of the irrigation needs in these regions while safeguarding coastal areas from degradation. Crucially, it integrates 11.3 GWh of renewable energy annually, underscoring its sustainability and enhancing its replicability for other water-deficient regions. • 33 hm 3 of water diverted to irrigation annually, avoiding sea discharge. • Reused wastewater increases water availability for irrigation communities. • Zero wastewater discharge to the sea, boosting sustainability. • Cost-benefit ratio over 12 supports rural agricultural development.