Streamflow, or channel runoff, is the flow of water in streams, rivers, and other channels, and is a major element of the water cycle. Waterflow expands the default rivers and lakes with smaller sidestreams. The record of flow over time is called a hydrograph. Msfs terrain look as we see is because of water flowing over the terrains; this scenery add those water features that have shaped terrains all around the world. These are visible mostly everywhere you fly; they reflect sun light and they are also visible on aircrafts terrain maps. Connecting lakes; rivers through small to medium size streams