This study emphasizes the importance of involving stakeholders in data formation related to assessments of hydropower development as a prerequisite for projects to be sustainable. It concerns the emerging dissonance between policy and its implementation after the UNCED and UNSSD conventions, when using hydropower development as a case. The new policies make it mandatory for implementing agencies to introduce or expand social considerations far beyond old practices. About a dozen project cases are assessed to show how policy change has influenced project design and implementation gradually. Readers will find a detailed account for new data formation methods through stakeholder mobilization. The book shows how the sustainability drive combines with democracy and grassroots involvement to influence stakeholder formation of project details.