Transcript Virginia’s Watershed

Virginia Watersheds
Mathematics & Science Center
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.
Watershed Movie
Courtesy of: Michigan Environmental
Education Curriculum
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.
Watersheds Vary In Size
Hydrologic Units
The United States is divided and sub-divided into
successively smaller hydrologic Units.
The Four Levels:
• Region
• Sub-Region
•
Account Unit
•
Cataloging Unit
What is a Divide?
A divide is the boundary that separates one
watershed from another.
What is a Tributary?
A tributary is a stream or river that contributes its
water to another stream, river or body of water.
Two Kinds of Water Pollution
• Point Source Pollution
• Nonpoint Source Pollution
Point Source Pollution
Courtesy: The Scottish
Agricultural College
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.
Nonpoint Source Pollution
Courtesy:www.deq.gov
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
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.