What is a Watershed ?

How Important is Water?

The Human Body is about 65% water (on

average).

The surface of planet Earth is covered by about

70% water.

Water Impacts Our Lives Everyday

Where does water come from?

The Water Cycle

Where does the rainwater go?

Downhill

Watershed divide: Ridges that separate two watersheds

Watershed : All of the land that drains water into one place

Watershed Divide

How many watersheds are pictured? 3

1

32

Watershed

The land that drains water into a stream, river or lake. It can be small or extremely large.

Atlantic

Gulf of Mexico

Pacific

Mississippi River Basin (Watershed)Ohio River Basin (Watershed)

What is the largest watershed (basin) in North America?In what “subwatershed” of the Mississippi will you find most of Kentucky’s land area?

Rivers

A

B

B

B

C

D

G

F

FE

H

I

1

23

4

5

6

7

8

Kentucky WatershedsLakes1) Kentucky 2) Barkley3) Cumberland 4) Dale Hollow5) Barren River 6) Nolin River7) Rough River 8) Cave Run

A) Mississippi B) Ohio C) Kentucky

D) Green E) Tennessee F) Cumberland

G) Big Sandy H) Salt I) Licking

Watersheds of the Kentucky and Green Rivers

By starting at the river mouth and drawing a line to separate two rivers from each other, the approximate watershed for that river can be drawn.

River Basins of Kentucky

Large drainage areas can be broken down into smaller ones that “nest” inside them.Sub-watersheds

Hypoxic Zone

Hypo = under, lowOxic = Oxygen

Area where very low level of dissolved oxygen prevents the existence of living things.

Caused by a process called Eutrophication

Cultural Eutrophication• Use of fertilizers and other phosphates in

watershed• Runoff to rivers• Excessive algae growth• Decomposition of dead algae by aerobic bacteria• Depletion of dissolved oxygen• Dead Zone forms

Hypoxic Zone Resources:http://www.gulfhypoxia.net/

http://www.ncddc.noaa.gov/hypoxia/