The world needs more renewable energy to combat climate change, and for many countries hydropower is a key part of their renewable energy mix. But we also need to protect the continuity of river systems and the unique ecosystems they support. So how do we balance the two goals? TNC's Hydropower by Design work has been a cornerstone of our conservation efforts as we respond to this challenge. A new paper in Science details an effort to use artificial intelligence (AI) to find ways to mitigate the environmental impacts of hydropower across the Amazon--3 million miles of river and 2.4 million square miles of forest--while achieving energy production goals.