ABSTRACT
The characteristics of the Paraná River Basin are governed by climatological, geological and hydrological parameters, as well as the human influences that alter the flow patterns and water quality status of the surface waters. Additionally, these surface waters recharge the aquifers of the basin, including the Guarani Aquifer, one of the largest continental groundwater reservoirs in the world. Most of the rivers in the basin are subject to pressures that have changed the quantity and the quality of its waters. This chapter provides an overview of the physiographic, climatological and hydrological characteristics of the basin and also provides a critical analysis of the threats to water resources of the Paraná River Basin caused by population growth and urbanization, and water use by industry and agriculture, as well as an analysis of the management options to address these threats. The threats to the quantity and quality of water in the basin come from hydroelectric development, and from both point and diffuse sources of pollution related to the discharge of sewage and industrial effluents, the use of fertilizers and agrochemicals in rural areas and intensive irrigation. This chapter includes a historical perspective of experiences within the basin related to the integrated management of shared waters, through the work of several national and international organizations and experiences of actions and results related to the integrated management of shared waters. There are still major challenges to be overcome, such as addressing the Cross-Border Critical Issues and other tensions in order to guarantee water sustainability and the democratic management of shared waters.
