Hydropower is the predominant renewable energy source globally and will play a key role in transitioning countries away from fossil fuels. Yet hydropower production is threatened by the effects of climate change, with significant implications for both energy security and the energy transition. In this policy brief, UC Berkeley PhD candidates Johnny Guy and Ishana Ratan, together with co-author Anthony Calacino, explore preliminary evidence from Brazil, Colombia, and Nepal that shows the multifaceted challenges hydropower-dependent nations face, and divergent responses governments have taken in response. They demonstrate why, in the face of increasing uncertainty, hydropower-dependent countries—already vulnerable to the impacts of seasonal disruptions to power supply—must develop robust strategies for load balancing and project risk management.