The GESAR group (Grupo de Estudos e Simulações Ambientais em Reservatórios, in portuguese) was founded in 2005 after a R&D project managed by the brazilian power utility company Furnas Centrais Elétricas S.A. an requested to Rio de Janeiro State University (UERJ) for the deployment of a simulator of the dynamics of hydropower plant reservoirs.

Located at Mechanical Engineering Department and committed to developing applied research, GESAR's portfolio comprises several projects that encompass different fields of study, such as numerical simulations, water quality assessment and database development. The projects are mainly granted by the main Brazilian fostering agencies: CAPES, FAPERJ, CNPq and FINEP.

Currently, the GESAR group is a Technological Development Unit (UDT) at Rio de Janeiro State University, able to provide consulting as well as research services to public and private companies. GESAR was also the pioneer to start up the UERJ's Graduate Program in Mechanical Engineering-PPG-EM activities in 2005, which is actively focused on forming new science personnel.