The Amazon River is the largest drainage basin in the world, covering over 6.9 million square kilometers in South America. During the rainy season, the river averages 40 meters deep and 40 kilometers wide, and the area covered by its water triples to over 350,000 square kilometers as the Amazon Basin floods the surrounding plains. The Amazon Rainforest is home to over one third of all species in the world and the Amazon river itself contains over 3,000 recognized fish species.