Indonesia, an archipelagic nation with more than 17,000 islands, faces persistent challenges in providing reliable electricity to remote communities. Decentralized hydropower offers a sustainable solution by utilizing abundant local water resources. Pico-hydropower and micro-hydropower systems provide cost-effective alternatives for rural electrification while supporting sustainable watershed resource utilization. In this study, a comprehensive identification framework was developed to evaluate the feasibility of integrating pico-hydropower with existing micro-hydropower systems to support community-based ice crystal production microenterprises in Indonesia. Candidate sites were selected using a purposive sampling strategy based on flow continuity, hydraulic head ($\Delta H$), discharge ($Q$), accessibility, and installation suitability. Spatial identification was performed through the integration of Google Earth imagery, unmanned aerial vehicle surveys, and total station measurements, followed by systematic field verification. Repeated field measurements were conducted to reduce measurement uncertainty and improve the reliability and reproducibility of the proposed methodology. Laboratory experiments and field validation were subsequently performed using a pico-hydropower portable turbine equipped with an undershot waterwheel configuration. A total of 60 potential installation sites were identified. Laboratory testing demonstrated that the prototype generated output under flow rates ranging from 11 to 25 L s$^{-1}$, producing sufficient electrical power for 50–100 W light-emitting diode lighting applications. Field validation at 30 representative sites confirmed the technical feasibility of the proposed system. The highest performance was observed at P21, where a rotational speed of 1,543 revolutions per minute and an output voltage of 3.1 V were achieved, providing electrical power equivalent to approximately 100 W under the prototype configuration, whereas the minimum validated performance was recorded at P15 under a discharge of 16 L s$^{-1}$. The results demonstrate that distributed pico-hydropower installations can effectively complement existing micro-hydropower infrastructure, supporting productive applications such as ice crystal production. The proposed framework provides a practical and scalable approach for expanding sustainable decentralized hydropower systems in geographically dispersed regions.