Howdy Drain Rangers!
Below are the instructions for our stormwater school activity:
- Read the introduction aloud
- Complete the activity questions
- Submit your answers to your teacher for credit
What is stormwater runoff and why is it a problem? When rain falls or snow melts in Bothell, where do you think the water goes? Does it soak into the ground? Does it sit in a puddle until it disappears? If you answered "yes" then you are partially correct-some water soaks into the ground or evaporates into the air.
But what happens to the rest of the rainwater? Some of it flows over hard surfaces (like roofs, parking lots, driveways, sidewalks, roads, etc.) and into the nearest storm drain, stream, or ditch. This water is called "runoff" or, sometimes, "stormwater runoff." Storm drains look like big grates in the road where water "disappears" when it rains. These storm drains carry water underground directly into your local streams without being treated.
As this water flows over our hard surfaces, it picks up harmful pollutants that we have left behind. Pollutants are anything harmful to our natural resources. Sometimes the pollution is something you can see like; trash, oil, soap, and dirt. Other times you can't see the pollution at all like when chemicals, bacteria, pesticides, and fertilizers are washed into a nearby creek.
This activity is meant to help you identify some sources of seen and unseen pollution around your home and help you calculate your impacts. For more information or tips on the answers visit the puget sound starts here website.
Name 3 sources of water pollution that can start at home
How can we reduce each of these types of pollution?
Calculate Your Stormwater Impacts
- Step 1- Calculate the area of your roof (width x length =area):
Width of building (in feet)=
Length of building (in feet)=
Width x Length = area of roof (square feet)
- Step 2- Calculate the volume of water (gallons) running off your roof in a 1-inch rain storm:
For every 100 square feet of roof surface, one inch produces 62 gallons of water
Area of your roof x .62 = volume of water
- Step 3 - Calculate your annual runoff:
Take the area of your roof number x inches of rain per year (Bothell is around 36 inches) x .62 =gallons per year
Imagine all that water rushing off of your roof, across your property and street, picking up pollution, then delivering those pollutants to the nearest stream without any treatment.