The hydroelectricity sector in Nepal will be affected by climate change. This study identifies areas where adaptation will be important in the coming years.

Assessing the future impacts of climate change on the hydroelectricity sector in Nepal is a challenge because of the country’s complex climate and hydrology, as well as the large changes in elevation that occur from low plains up to the high mountains. Projections of future climate change show high uncertainty, with large differences across future scenarios and between climate models. This makes adaptation planning difficult.

To address these challenges, this study used a climate risk assessment (CRA) methodology based on a bottom-up decision-scaling approach. The method identified three types of adaptation where decisions (or policy) will be important over the next five to ten years, and provides information to help address both current climate variability and long-term climate change.

The three types of adaptation are:

1. Immediate actions that address the current risks of weather and climate extremes (the adaptation deficit) and build resilience to future climate change. These include early low- and no-regret actions, which provide immediate economic benefits as well as future benefits under a changing climate. These activities are focused on current hydropower plants.
2. The integration of adaptation into immediate decisions or investments with long lifetimes (climate smart planning), focusing on the new (planned or candidate) hydroelectric plants that will be built over the next decade or so. These plants will be exposed to uncertain future climate change. There will therefore be a greater emphasis on low-cost design or flexible or robust options that perform well under uncertainty.
3. Early monitoring, research and learning to start planning for the future impacts of climate change. This includes investing in information and learning to help future decisions

Key messages

• Current climate and hydrological variability is a major challenge for Nepal’s hydropower sector.
• The impacts of climate change on hydropower are uncertain, due to the lack of reliable long-term hydro-meteorological data and the high uncertainty associated with future climate change in Nepal.
• The greatest impacts of climate change are likely to be increased climate-induced hazards, such as sediment load, extreme floods and geo-hazards (glacial lake outburst floods).
• The current power system suffers from an inefficient power mix leading to high economic costs at the system (national) level.
• Climate change impacts are additional to other factors and uncertainties (i.e. additional to current climate variability, and institutional and regulatory issues).
• Adaptation pathways can help address the challenges associated with adapting the hydro sector. A suite of options is needed, i.e. it is not a case of ‘one size fits all’.
• Adaptation needs to be designed to the specific context, hydro plant and vulnerability.
• There are low-regret options to adapt the hydro sector in Nepal, across the range of risks and climate-induced hazards, for different types of plants.
• The institutional context is important for mainstreaming climate change into future sector development plans and policies.