The protection, conservation, and management of water resources and water quality depend upon all of us understanding the basic concepts of hydrology as well as that of watershed and watershed health. The science which deals with water and its movement in the hydrologic cycle is known as hydrology. The hydrology of small watersheds is different from that of the large watersheds. The watershed is a fundamental concept in hydrology and is the basis for understanding the hydrologic processes and for the planning and management of water resources. An understanding of the various hydrologic processes within a watershed is essential to keep the watershed in good health through the effective management of rainwater/runoff, soil water and soil erosion. Precipitation provides the primary input of water into the watershed. Depression storage is the amount of rainwater stored in the micro or macro depressions on the watershed surface before starting of runoff.