“There’s a pencil in the storm drain! We need to get it out!” exclaimed 4th grade students at Main Street Elementary after they found several objects in a school storm drain they knew would eventually make its way to a local creek.
Over the course of four lessons, students investigated the concept of a watershed, learned about permeability and engineered designs to prevent pollution from entering a storm drain. Students built miniature watershed models to examine how water flows over various landforms and eventually collects in a basin. Using sugar sprinkles as “pollutants’, students made it rain on their models and examined how water has the ability to pick up anything in its path. In a visit to Soquel Creek, students sprayed water on diverse surfaces to determine what happens when rain hits various surfaces. As they discovered, sand, soil and rocks allow water to enter the surface whereas surfaces such as concrete and plastic forces the water to runoff. Applying their knowledge gained they predicted whether the water would eventually make its way to the creek depending upon the surfaces the water flowed over. Knowing that water had the ability to pick up trash and other pollutants and sweep them out either to a local creek or into a storm drain, students work together in groups to engineer tools that would allow water to enter a storm drain while preventing trash or pollutants from entering. Below are some of the engineering design ideas of the Main Street Watershed Rangers:
- A permeable surface covering the length and width of a storm drain that would allow water to get through but capture trash or pollutants before it enters the storm drain
- A robot that would monitor a storm drain and prevent trash or pollutants from entering
- A permeable barrier surrounding a storm drain that would allow water to go through but prevent trash or pollutants from entering the storm drain.
- Cover a storm drain with a layer of permeable fake grass that would allow water to enter but not pollutants
- Layers of plants, soil, rocks and cement with pipes to allow water to exit into the ocean but capture trash in the upper layers.
Check out the Watershed Ranger designs below.