A dual-framework approach to assessing the sustainability of small hydropower potential sites: A case study of the Citarum Watershed, Indonesia

This study addresses the gap in integrated sustainability assessments for early-stage hydropower planning in data-scarce regions by applying a dual-framework approach to four potential small hydropower (SHP) sites in the Citarum Watershed, Indonesia. We integrated the Hydropower Sustainability Assessment Protocol (HSAP) with a Multi-Aspect Sustainability (MSA) framework, which employed a Rapid Appraisal Process based on expert elicitation (12 experts, three-round Delphi) and leverage factor analysis across environmental, social, economic, and technical dimensions. Data were derived from geospatial analysis (GIS, SWAT modeling), national statistics (BPS, 2024), and disaster risk indices (BNPB). The analysis quantified current sustainability scores (0-100 scale) and future condition projections for each site. The findings reveal a critical disconnect between technical-economic viability and socio-environmental sustainability. Site 3 achieved the highest technical score (80.67), but Site 1 demonstrated the most balanced overall profile (60.73) due to superior environmental (88.14) and economic (56.25) performance. Site 2 was least favorable (42.90), driven by acute pressures: high population density (1,228 persons/Ha), agricultural dependence (80%), and multi-disaster risk. Statistical validation (bootstrap resampling, p < 0.01) confirms significant sustainability differences between sites. The integrated framework proves replicable for decision-makers, identifying site-specific leverage factors (e.g., water flow, population density, employment) to guide targeted interventions that balance energy development with ecological and social priorities in complex, data-scarce watersheds.