The participants of the 4th International workshop on Regional Approaches to the Development and Management of Reservoirs in La Plata River Basin, event which took place in Salto Grande, Argentina/Uruguay, from 29 November to 2 December 2005, have submitted their conclusions and drafted recommendations for the consideration of the governments of the member states and the Intergovernmental Coordinating Committee of La Plata River Basin. These highlight the need to take into consideration the effects of climate change in the joint planning of water and energy resources, consolidate the process of integrated water resources management of reservoirs and their basins, and generalize public participation in decision-making concerning reservoir development and management. It was decided that 2 working groups would be created to prepare the development of an environmental reservoir monitoring database and to work on standardisation of water quality data; and the creation of a regional initiative to consolidate information concerning the economic valuation of the effects of eutrophication and cianotoxines was recommended.