Hydrologic Systems encompass all of the interrelated physical structures and devices as well as the natural environment (including precipitation, evaporation, streamflow, surface runoff, groundwater movement, etc.) that effect, and help manage, the movement, distribution, and properties of water. This also includes knowledge of the fundamental principles of hydrology necessary to analyze and evaluate environmental conditions and determine the characteristics of hydrologic systems needed to meet design objectives. This concept is important to Engineering Literacy, as it enables one to leverage the knowledge of runoff, stream flow, soil moisture, and ground water flow to innovate tools and methods in water distribution and collection necessary for sustaining, as well as enhancing, a community’s living conditions and economy. For example, methods of data collection and error analysis associated with water in hydrology and water resources, assist in the development, construction, and application of systems necessary to manage a community’s water resources.