1. Mathematics & Science Center
Virginia Watersheds
Mathematics & Science Center

2. What is a Watershed?
It’s the land that water flows across or under on it’s way to a stream, river or lake.
A watershed with its small streams and larger river can
be compared to a leaf with its sub-veins and main vein.

3. Courtesy of: Michigan Environmental
Watershed Movie
Courtesy of: Michigan Environmental
Education Curriculum

4. We all live in a Watershed
Courtesy of DCR’s Soil & Water Conservation Programs
In the mountains or where the land is flat.
In cities, forests and on farms.
Even plants and animals live in a watershed.

5. Watersheds Vary In Size

6. Hydrologic Units The Four Levels: Region Sub-Region Account Unit
The United States is divided and sub-divided into
successively smaller hydrologic Units.
The Four Levels:
Region
Sub-Region
Account Unit
Cataloging Unit

7. What is a Divide?
A divide is the boundary that separates one watershed from another.

8. What is a Tributary?
A tributary is a stream or river that contributes its water to another stream, river or body of water.

9. Two Kinds of Water Pollution
Point Source Pollution
Nonpoint Source Pollution

10. Point Source Pollution
It’s usually easy to figure out where point source pollution comes from. If you see a pipe emptying into the water, that’s a point source. You can point to where it’s coming from.
Courtesy: The Scottish Agricultural College

11. Nonpoint Source Pollution
Courtesy:
Nonpoint source pollution comes from places you can’t easily identify:
Rain washes loose soil off construction sites
Rain washes oil and litter off parking lots
Extra fertilizer on lawns wash into our water
Acid rain exhaust from cars

12. Why Do We Study Watersheds?
Every place in Virginia belongs to a watershed.
The quality of water in each stream and river depends in large part on the land use in the watershed.
Land used for residential, agricultural, or commercial areas can either hurt or support water quality.
Knowing where your water comes from is important, especially if any problems occur upstream.