North Carolina Department of Environment and Natural Resources
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What is a River Basin?
A river basin is the land that water flows across or under on its way to a river. Just as a bathtub catches all of the water that falls within its sides, a river basin sends all of the water falling within it to a central river and out to an estuary or to the ocean.

A river basin drains all of the land around a major river. Basins can be divided into watersheds, or areas of land around a smaller river, stream, or lake. North Carolina is made up of many watershed connected to each other. Within each watershed, all water runs to the lowest point – a stream, river, lake, or ocean. On its way, water travels over the surface of the land across farm fields, lawns, and city streets, or it seeps into the soil and travels as groundwater. Large river basins are made up of many smaller watersheds.

Everyone lives in a river basin. It is part of your ecological address. You
can change what happens in your river basin, for good or bad, by how you
treat the natural resources – the soil, water, air, plants and animals. As
water moves downstream, it carries and leaves behind gravel, sand, and silt.
It also carries bacteria and chemicals. Whatever happens to the surface water and groundwater upstream will eventually have an effect downstream. Even if
you don’t live near a river, you still have an effect on your river basin.
How River Basins are Formed
Erin Hancock, NCWRC
Tree
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Crumpled Paper
Crumpled Paper
Crumple Paper

Take a piece of paper that you are done using. Crumple it up into a ball. Now gently open up the paper, but don't flatten it out completely. The highest points
on the paper represent the mountaintops and the lowest wrinkles, the valleys. Choose one color of water-soluble marker and use it to mark the highest points
on the map. These points are the mountain ridgelines. Choose a second color
and mark the places where different bodies of water might be: creeks, rivers, and lakes. With a third color, mark four or five places to represent human settlements: housing tracts, factories, shopping centers, office buildings, schools, etc. Try sprinkling a powdered material, such as cinnamon, red pepper, or cocoa powder, to demonstrate how pollutants flow through the watershed. Use spray bottles to lightly spray the topographic watershed maps. The spray represents water falling into the watershed (Source: VA Love-A-Tree).
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NCDENR, Division of Water Quality

1617 Mail Service Center, Raleigh, NC 27699-1617      (919) 807-6363      Fax  919-807-6494 27699-1601