This study presents a novel methodology for prioritizing erosion-prone watersheds in the Song River basin using a combination of morphometric indices, Analytical Hierarchy Process-Technique for Order of Preference by Similarity to Ideal Solution (AHP-TOPSIS) and geospatial technology. The study river basin drains the central and eastern part of the Doon Valley, in Uttarakhand and makes a confluence with the Holy Ganga near Virbhadra, covering an area of 1047.120 km2. The study area poses significant environmental challenges, particularly in terms of erosion and to address this, the current study integrates morphometric analysis with multi-criteria decision-making techniques to identify high-priority areas for erosion mitigation efforts. The AHP-TOPSIS method is then applied to rank sub-watersheds based on multiple parameters, providing a comprehensive understanding of priority areas. Geospatial technology enhances the analysis by facilitating spatial visualization and precise delineation of erosion-prone zones. The study shows the basin is a fifth-order with a dendritic, parallel and subparallel drainage pattern and elongated morphology. The results reveal distinctive high-priority zones, where sub-watersheds SW7, SW8, SW6 and SW5 exhibit heightened vulnerability to erosion. Ground truthing validates these results, affirming the efficacy of the integrated approach. This study’s novelty lies in its amalgamation of methodologies, offering a systematic framework for prioritizing watershed management interventions. The outcomes of the study are vital for policymakers and stakeholders, guiding the formulation of targeted conservation strategies and the implementation of integrated watershed management programs. By focusing on erosion-prone areas, this present work will contribute to sustainable resource management and ecosystem preservation in the Song River Basin and beyond.