This unit focuses on water reclamation. It features a simulation that allows students to follow water from pristine and logging forests through residential and commercial areas into wetlands and urban areas. Students have the opportunity to explore a number of water quality issues, including how land use affects water quality, how to collect and analyze useful data related to water quality, and how water filtration systems work, both in general and in their communities. The lessons lead up to an actual engineering project including steps to design, build, and operate a wastewater filter. The unit as a whole contains a number of activities that build upon each other, but which can be used as stand-alone activities as well to teach individual concepts. A specific example is the Colorado River Basin Activity.