This study advances prior approaches by integrating Water Evaluation and Adaptation Planning (WEAP) modelling with a novel Enhanced Sustainable Development Goals (SDG) Impact Assessment Framework (ESIAF) to holistically evaluate irrigation scenarios in water-stressed agricultural regions such as the Indus Basin. Applied to the Chaj Doab region within Pakistan's Indus Basin, this research fills a critical gap in canal-specific, SDGlinked planning for water-stressed agricultural regions. In this integrated approach, the WEAP model simulated physical system responses, quantifying that the optimal scenario (Scenario 3) improves water-use efficiency by 32.4 % (to 67.55 kg/m3) and increases crop yields by 74 %. The ESIAF sustainability assessment reveals this scenario achieves a Final Sustainability Score (FSS) of 0.66 with a Sustainability Balance Index (SBI) of 0.86, demonstrating robust alignment with SDG 6 (Clean Water and Sanitation), SDG 2 (Zero Hunger), and SDG 8 (Decent Work and Economic Growth). Conversely, climate change projections (Scenario 5) indicate system reliability could plummet to 34-35 %, underscoring the urgency of adaptive measures. The WEAP-ESIAF coupling provides a replicable decision-support tool that offers direct insights for implementing Pakistan's National Water Policy (2018) and guiding sustainable irrigation investments in semi-arid, glacier-dependent basins.