In this four-lesson unit, students collect evidence to construct explanations that rain causes changes to their school yard. They develop models to explain rapid and slow changes to the school yard, and observe these changes at a broader watershed level. Finally the students apply the information to an engineering problem where they use their model to develop a solution that will slow down or stop rainwater from changing their school yard.

The first lesson of the unit takes place after it rains. This day, using a tablet or digital camera, students go outside and take pictures to collect evidence that rain causes changes to their school yard. Back in the classroom, they explain how their evidence demonstrates that a rain event occurred. They use this evidence to develop oral and written claims through discussion and creating sentence strips that help them articulate their ideas.