This report provides detailed proceedings from the Workshop “Integrating Modeling of the Interactions, Connectivity, and Interdependence of Water Systems and Ecosystem Services in the Lower Mekong Basin” that was held at the Center for Khmer Studies in Siem Reap, Cambodia, June 12-13, 2013. This was the 2nd of three Workshops held under funding from the US National Science Foundation (NSF) Water Sustainability and Climate (WSC) program, under a grant awarded to Florida State University, The University of Chicago, The University of Florida and Stanford University (NSF Solicitation 11-551, Award 1204609).