Watershed Definition

STEM Lessons at Home

"Everyone lives in a watershed"

Why is knowing your watershed important? Well, watersheds contain all the water bodies that supply our drinking water, water for agriculture and manufacturing, offer opportunities for recreation like kayaking and swimming, and provide habitat to plants and wildlife.

Rain and snow fall to earth (precipitation) some of it evaporates, some soak into the soil, and some fills lakes and rivers, eventually flowing into the ocean.

Water that runs above the ground. 

Watersheds come in many shapes and sizes, and smaller watersheds exist inside larger ones.
• Coasts
• Forests
• Grasslands
• Deserts
• Farms
• Your School 
• Your neighborhood 

What watershed do I live in?

For example, if you live in the Portland area, you may live in any of these watersheds, all connected as part of one major river basin.

Watersheds of Portland:
- Columbia Slough
- Willamette Mainstem
- Willamette Tributaries
- Fanno Creek
- Johnson Creek
- Tyron Creek

What major river basin do I live in?

- Willamette Basin

Save our One World Ocean

Overland flow or runoff water can be seen on the street flowing into a street drain. Any litter or invisible toxins on the ground are picked up by the runoff water and carried to a street drain or underground into urban streams, rivers, lakes, and the ocean.

Marine Biology for Kids - Ocean Debris Kit
Plastic fragments and Microplastics found on American beaches.

How do watersheds connect to the ocean?





salmon runs

Salmon runs

coral reaf

Coral Reefs

How Does Litter Get in the Ocean?

How are all oceans connected?

  • Why are there ocean currents?
  • What’s the connection between marine animals and ocean currents?
  • How do pollutants and plastics travel in the ocean and where do they go?
  • What human activities impact watersheds?
  • How are people connected to water?
  • Who is eating plastic?
  • What can humans do to help?
  • Seabird-photo-scaled

    What can you do?

    Get your Watershed Course Guide