The Watershed Concept: All of the water on Earth is stored in the oceans, ice caps and glaciers, groundwater, lakes, atmosphere, rivers, plants, animals, and soil. It is the movement of this water, via precipitation, runoff, evaporation, transpiration, and infiltration that has the potential to move pollutants from one place to another. Watersheds are all of the land area draining water (through runoff) into a particular stream, river or lake. Track the movement of water through the hydrologic cycle and explore ways in which scientists and engineers work to manage water resources. Supports water unit lesson 3.