Sandra Postel is one of the world's leading authorities on freshwater issues. She directs the independent Global Water Policy Project and lectures, writes, and consults on international water issues. She is a Freshwater Fellow of the National Geographic Society, and serves as lead water expert for the Society's freshwater initiative. Sandra is the author of several acclaimed books, including the award-winning Last Oasis, the basis for a PBS documentary. Her essay "Troubled Waters" was selected for Best American Science and Nature Writing. Sandra is a Pew Scholar in Conservation and the Environment, and has been named one of the "Scientific American 50" for her contributions to water policy.