It All Runs Downhill – Make a model of a watershed,

Nowadays water pollution comes mostly from stormwater. Rain and snow are usually clean when falling from the sky. Once water flows over and through the ground it picks up chemicals, oil, animal wastes, and other contaminants.

This changes clean water into polluted runoff, which is also called “nonpoint source pollution.”

Follow these instructions to make a watershed model you will learn how rainfall carries pollution into the ocean and other water bodies.