With over 6,000 rivers and streams, Nepal has an enormous potential for hydropower. However, energy shortages are chronic. Nepal imports both electricity and fossil fuels from its neighbors. Across its countryside, many families rely on firewood to cook. Hydropower advancement has been perceived as one of the vital drivers in ideally using the accessible water assets towards accomplishing the target of energy security and green growth. Sustainability is a talk planned to advance new systems of energy, water and ecological system. To promote sustainable hydropower development, there should be engagement with the key stakeholders in Nepal’s hydropower development sector, including government and private hydropower developers. Also collaboratively identified key challenges and data gaps, such as standardized data collection guidelines and the need for data on extreme events, such as glacial lake outburst floods, landslides, and avalanches, as well as on year-round river discharge to better understand regional and localized hydrological cycles. Improving research on each basin and making such data accessible to hydropower developers can contribute to maintaining environmental sustainability. To ensure that social and environmental concerns for addressing the hydropower development, the supporting document of the ‘Hydropower Environmental Impact Assessment Manual (HP-EIA) of Nepal’ which provides guidelines for developers to identify and manage environmental and social risks and impacts and guard against unforeseen risks and impacts. Other aspects of sustainable hydropower development are more social in nature, including policies, plan and program related to energy trade and issues surrounding where benefits from that trade accrue.