Presented by Charlotte MacAlister, Birhanu Zemadim, Teklu Erkossa, Amare Haileslassie, Dan Fuka, Tammo Steenhuis, Solomon Seyoum, Holger Hoff, Kinde Getnet, and Nancy Johnson to the Nile Basin Development ChallengeScience and Reflection Workshop, Addis Ababa, 4-6 May 2011