Stormwater Pollution
The Issue
Stormwater is the polluted runoff gathered from rain, severe thunderstorms, and even snow from roads, parking lots, and other impervious surfaces across the watershed, where runoff collects pollutants and carries them downstream, ultimately into the Great Lakes. When it rains/snows, stormwater picks up whatever is in the street: trash, oil, waste, fertilizers, pesticides, chemicals, pet waste, and sediment.
Surface Runoff and Stormwater
These two terms are often used interchangeably and for our purposes can be as well.
Surface runoff accounts for much of the recharge of our surface waters following precipitation events (rainfall or snow-melt). Because of the speed that water can gather as it moves across a surface, runoff also helps shape our land through erosion. Stormwater is typically related to our built environment and how humans cause runoff to behave differently than it naturally would.
This 2-minute video is an overview of stormwater impacts.
Types of Surfaces
Surfaces can be categorized as permeable (allowing water to flow through) or impermeable (not allowing water to flow through). You may also see the terms pervious and impervious. Note that sometimes highly compacted soils, soils typically being considered permeable, may actually be impermeable.
How much of your site is permeable surface and impermeable surface. How does this impact the way your site experiences a rain event or snow-melt?
Take Action!
Review: The Great Lakes and humans in their WATERSHEDS are inextricably interconnected. (Great Lakes Literacy Principle #6!)
RESOURCE: This Indigenous STEAM Water Walking Activity and this ISTEAM Watershed Walking Activity will help students explore their place and watershed by exploring the following questions: Where does the water come from? Where is it going? Who does it encounter along its journey?
RESOURCE: The Follow The Drop Activity will help students observe and calculate rainfall, area and runoff on their school grounds (or at another place you are providing stewardship at).
RESOURCE: Use the River Runner map visualization tool to watch the path of a raindrop as it moves through its watershed anywhere in the United States.
Green Infrastructure
Green Infrastructure for Runoff | Elizabeth Fassman-Beck, Ph.D.
Section 502 of the Clean Water Act defines green infrastructure as "...the range of measures that use plant or soil systems, permeable pavement or other permeable surfaces or substrates, stormwater harvest and reuse, or landscaping to store, infiltrate, or evapotranspirate stormwater and reduce flows to sewer systems or to surface waters."
RESOURCE: Learn about Green Infrastructure basics and applications including bioswales, rain gardens, collecting rainwater and more on this EPA resource page.
RESOURCE: Learn about the history, importance and types of Green Infrastructure by reading this article from the National Resources Defense Council.
Taking Action: PBSE Opportunities
Rain Gardens: Learn more about implementing a rain garden in this FREE Master Rain Garden Class.
Bioswales: Bioswale Fact Sheet from SE Michigan Council of Governments.
Other types of green infrastructure your students may want to explore:
Rainwater Harvesting
Planter Boxes
Green Roofs
Urban Tree Canopy
PBSE in Action: Au Gres Sims High School
<<VIDEO: Solving Stormwater Pollution at Riverside Park!
RESOURCE: Explore this Google Site created by Au Gres Sims High School students about their green infrastructure projects including a bioswale and rain garden.