Primary objective of this lecture is to present on Streams and Floods. Stream is a body of running water that is confined in a channel and moves downhill under the influence of gravity. Stream erosion and transportation generally increase as a result of a flood’s velocity and discharge. Here also focus on Hydrologic Cycle. Hydrologic Cycle is the movement of water and water vapor from the sea to the atmosphere, to the land, and back to the sea and atmosphere.