Students gain a basic understanding of the properties of media soil, sand, compost, gravel and how these materials affect the movement of water (infiltration/percolation) into and below the surface of the ground. They learn about permeability, porosity, particle size, surface area, capillary action, storage capacity and field capacity, and how the characteristics of the materials that compose the media layer ultimately affect the recharging of groundwater tables. They test each type of material, determining storage capacity, field capacity and infiltration rates, seeing the effect of media size on infiltration rate and storage. Then teams apply the testing results to the design their own material mixes that best meet the design requirements. To conclude, they talk about how engineers apply what students learned in the activity about the infiltration rates of different soil materials to the design of stormwater management systems.

Students are introduced to innovative stormwater management strategies that are being used to restore the hydrology and water quality of urbanized areas to pre-development conditions. Collectively called green infrastructure (GI) and low-impact development (LID) technologies, they include green roofs and vegetative walls, bioretention or rain gardens, bioswales, planter boxes, permeable pavement, urban tree canopy, rainwater harvesting, downspout disconnection, green streets and alleys, and green parking. These approaches differ from the traditional centralized stormwater collection system with the idea of handling stormwater at its sources, resulting in many environmental, economic and societal benefits. A PowerPoint® presentation provides photographic examples, and a companion file gives students the opportunity to sketch in their ideas for using the technologies to make improvements to 10 real-world design scenarios.

Students are presented with a guide to rain garden construction in an activity that culminates the unit and pulls together what they have learned and prepared in materials during the three previous associated activities. They learn about the four vertical zones that make up a typical rain garden with the purpose to cultivate natural infiltration of stormwater. Student groups create personal rain gardens planted with native species that can be installed on the school campus, within the surrounding community, or at students' homes to provide a green infrastructure and low-impact development technology solution for areas with poor drainage that often flood during storm events.

Unit Title: Urban Runoff and Its Impact on the Community and BeyondAuthor: Anthony Jordan, Franklin High School, Franklin Public SchoolsGrade Level: 9-12Context:  This unit of study combined mathematics, environmental science, and literacy while also incorporating a real world context. Students began the unit of study by looking at specific examples of environmental impacts of rainwater runoff and the contaminants they contain. In addition, students used these articles to build context knowledge and dive deeper through research on the reasons behind stormwater runoff, the systems in place, and solutions to solve this problem on a local, national, and global level. Afterwards students began to incorporate how to calculate the amount of stormwater runoff and utilized GIS and google earth to develop a deeper understanding of how to accurately calculate the area of impervious surfaces. Finally, students compared the amount of runoff calculated and were able to construct a project on how to address building a greener school.