This document discusses India's drainage systems and major river basins. It outlines the Himalayan rivers of the Indus, Ganga, and Brahmaputra that drain northern India, and describes their respective river systems. It also mentions the peninsula rivers of the Narmada, Tapi, Godavari, Mahanadi, Krishna, Kaveri and discusses India's lakes and their role in the economy as well as the issue of river pollution.