A presentation on transboundary impact assessments (TIAs) in the Mekong River and other international watercourses. The presenter outlines research by the Environmental Law Institute, University of Tokyo and United Nations Environment Programme to develop a common template for comparing the impacts predicted in a TIA with actual impacts. The presenter then discusses five case studies and lessons learned. Case studies are projects in the Lancang-Mekong River; Se San River Basin; Lake Victoria; the Lesotho Water Highlands and the Epupa Dam. Presented at the China Environment Forum, 26 February 2007.