Various types of water, ranging from alkaline to highly acidic, result in whitewater, blackwater and clearwater rivers in the Amazon Basin. The different water types have a major influence on aquatic productivity and biodiversity. Thickness of river lines does not represent river discharge.

Amazonian rivers are classified locally and in much of the literature by their colors. Several processes lead to river color, the most important being the amount of sediments they transport. While transitions between water types exist, in general, three types of rivers are recognized based on their general color: whitewater, clearwater and blackwater rivers.