Stormwater Marble Run

In this activity, participants will learn fundamental concepts of guiding stormwater and will explore different best management practices (BMPs). BMPs is a term that describes methods of treating stormwater runoff through the prevention and reduction of stormwater pollution. There are 3 main concepts that BMPs follow to reduce stormwater runoff:

• Slow it down

• Spread it out

• Soak it in

Stormwater Marble Run! promotes awareness about healthy watersheds by teaching participants the importance of BMPs to reduce the amount of stormwater runoff and pollution that goes into local rivers, streams, and the Chesapeake Bay. While this resource has been designed for students in 6th grade and up, it can be adapted for all kinds of audiences. See suggestions in our section on Adaptations.

Participants should understand the main principles of Best Management Practices (BMPs) and stormwater.

• Stormwater runoff is one of the leading pollution sources to the Chesapeake Bay. We can reduce runoff through the use of BMPs.

• BMPs are methods used to treat stormwater runoff before it enters streams, rivers, and the Chesapeake Bay. “Treating” stormwater is what happens when soil slowly absorbs the pollution from the water, allowing much cleaner water to enter the Chesapeake Bay.

• BMPs reduce runoff by slowing it down, spreading it out, and soaking it into the ground.

• Some of the common types of BMPs are rain barrels, rain gardens, and conservation landscapes.

Hands-On-Activity: Participants will create structures using marble run pieces in order to achieve the slowest time for the marble to move through the structure.

Optional Outdoor Activity: Talk a walk outside and identify any BMPs or native plant gardens that may be on site.

Reflection: Ask your participants what they learned and how they can take action for a healthy watershed.

Essential Question to Explore: How do BMPs help treat and manage stormwater?

Materials You Will Need

• Marble run sets

• Marbles

• These and other support materials available for loan to Stewards: click here to request outreach materials.

• Timer/stopwatch (please supply your own - remember most folks have a stopwatch function on their phones.)

 Directions

a) Exploration

1. 1. Ask participants what they already know about pollution issues affecting the Chesapeake Bay.

   2. What are some factors that contribute to stormwater runoff?

   3. Define the following terms:

• Stormwater – Rainwater that runs off hard surfaces collecting sediment, pesticides, fertilizers, and bacteria that ultimately ends up in our streams, creeks and rivers.

• Best Management Practice (BMP): A term used to describe methods of treating stormwater runoff. BMPs are a means of preventing or reducing the amount of stormwater pollution.

1. 4. Discuss how we use BMPs to mitigate stormwater runoff.

      • Slow it down

      • Spread it out

      • Soak it in

1. 5. Share a few examples of BMPs that are commonly used and briefly describe them (available in Rainscaping Field Guide):

• Rain Gardens

• Conservation landscapes

• Rain Barrels

• Step-Pool conveyance (optional)

• WSA Virtual Stormwater Tour Video: Timber Creek (optional)

b) Hands-on-Activity

1. Gather the participants into groups, with an ideal group size between 3-6 (5 groups max with WSA materials). 

2. Each group will receive a pre-made bag of marble run structural pieces. 

3. The objective is for each group to create a structure using the pieces provided for the marble to go through the slowest (to represent BMPs designed to slow water flow). The structure must be free standing and can only use the pieces provided. Participants are not required to use all of the pieces provided. 

4. The participants will have 10 minutes to work with their groups to create the structures. After the 10 minutes is up, the instructor will check to see that each group has a functioning model.

5. Ideally the instructor will have participant groups self-test their models. Using stopwatch functions on phones, have participants start their time when the marble drops at the top of the structure and stop the time when it ends. Record time(s). If an Instructor-led format is required, starting with 1 group at a time, have the group drop the marble into the starting track on the count of 3, with the instructor using a stopwatch to track how fast the marble goes through the structure. The instructor will record each group’s run time and the group with the longest time wins.

• If the marble gets stuck on the track for 3 seconds of not moving, stop their time. They can get a second try, but if the marble stops again move on to the next group. For the first iteration of the exercise it’s great learning to discuss what happens when a BMP is too flat!

• If the marble flies off of the track, they can go a second time. Just as above, it can be very helpful learning to discuss what happens when a BMP is designed too steeply.

6. Have a discussion with the group about the exercise:

• What piece worked the best for your group in terms of slowing down the marble? Why do you think that is so?

• What could the different pieces symbolize for stormwater management?

• How would you design the structure differently to help slow down the marble?

c) Continued Exploration Outside (optional)

Take a short walk outside and try to identify what things are helping reduce stormwater runoff and things that are contributing to runoff (trees and gardens vs. impervious surfaces and pollution sources).

d) Reflection

Get the audience thinking about what they've learned and how they can take action by encouraging the installation of stormwater BMPs and planting native plants. Underscore the value of maintaining BMPs. What happens if a BMP doesn’t get maintained?

Optional: Can they think of other “best practices” that they can adopt to reduce pollution entering the Bay?  (Lawn Car, Car Wash, Household Cleaning Products, etc.). As the instructor consider this Behavior Change reference before asking this question.

e) General Suggestions

• Before starting the lesson, make sure that there is a flat, steady surface upon which each group can build their structures.

• Make sure that no one is touching the table that the structure is on when running the marble through the course.

• For smaller groups (15 people total or fewer), add in additional marble track pieces.

• Consider having each group go through the marble run once. After making observations of how the marble moved during their structures, have them redesign their structures to further slow the marble, based on their observations. 

Adaptations for Different Audiences

• K-3: Give younger students additional time to design their tracks, and give them opportunities to test their marbles on the tracks before they compete.

• Middle School and High School: As written.

• Mixed Age / Families:  As written.

Adaptations for Different Formats

• Indoor Or Outdoor Classroom Setting: As written.

• Program for a Small Audience (10 people or fewer): Follow recommendations above in General Suggestions.

• Tabling station: Give people who visit the table an opportunity to build a structure; record times on a general board and track who has the slowest time over the course of the event.

Feel free to check out and use the slideshow for Stormwater Marble Run! to introduce the topics of stormwater runoff and BMPs.

Key Terms

• BMP - A term used to describe methods of treating stormwater runoff. BMPs are a means of preventing or reducing the amount of stormwater pollution.

• Rain Garden - A Rain Garden is a shallow landscaped depression that receives runoff from surrounding rooftops, driveways, or yard areas.

• Conservation Landscape - An intentional outdoor, natural design that establishes the features of an area of land in a way that incorporates environmentally sensitive design, low impact development, non-invasive native plants, and/or integrated pest management.

• Stormwater Runoff - Rainwater that passes over hard surfaces collecting sediment, pesticides, fertilizers, and bacteria that ultimately ends up in our streams, creeks and rivers.

• Slow it Down, Spread it Out, Soak it In - These three main functions of stormwater BMPs help guide conservation landscape design and maintenance.

Fun Facts

www.chesapeakebay.net/issues/threats-to-the-bay/stormwater-runoff 

See how much water-borne litter was collected by the Chesapeake Bay’s own Trash Wheel family and learn more about managing stormwater from our friends at the Chesapeake Bay Program.

The Watershed Journey of a Raindrop

Have you met Rio the Raindrop? Checkout our friend’s journey here to learn more about how water travels across our region and ultimately becomes part of our shared Chesapeake Bay.