MCSEEP’s Watershed Lesson Warm-Up
How Watersheds Work by Tiffany Connors
Surely you've spent time cooped up at home during a rainstorm. Hours later, the land, streets and
buildings outside look completely dry. Have you ever wondered where all that rain goes? We know that
much of the water gets absorbed by the ground and by plants, but where does the rest of it end up? It
eventually drains into the surrounding lakes and rivers, but it must get there via watersheds.
Where are these watersheds? Here's a hint: You're sitting in a watershed right now. The Environmental
Protection Agency (EPA) defines a watershed as any body of land that flows downhill into a waterway.
Basically, "watershed" is a broad term used to describe how water flows across land to feed streams,
rivers and lakes [source: EPA]. All of these watersheds fit together like puzzle pieces to form our land
masses.
All land masses feed into a body of water, whether it feeds into the Mississippi River or your backyard
pond. Obviously, water cannot travel uphill, so all watersheds are determined by topography. That means
if you live on one side of a ridge and your neighbor is on the other side, you live in different watersheds.
That also means that watersheds vary greatly in size, depending on the highest points surrounding it.
A watershed can be thousands of square miles, or it can be a few acres draining into a pond [source:
EPA]. There are millions of watersheds in the world - 2,100 small ones in the United States alone
[source: NatureServe]. However, a watershed is more than just a piece of land that collects the rainwater
and dumps it into the river. Anything that ends up in a watershed ends up in a body of water, including
pollutants like discarded motor oil or paint, or sediments from trees cut down due to construction. These
and other pollutants can contaminate a water supply, erode the land surrounding the body of water and
disrupt aquatic habitats. Maintaining the health of our watersheds is vital to our ecology, but how does
this affect you? Why should you care about watersheds?
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MCSEEP will be bringing a watershed model to your class to explore the McHenry County
watersheds and who protects them. Here is some information to read and consider prior to the
lesson.
“We all live downstream”
Have you ever heard the saying “We all live downstream”? Is there truth to this saying? Watch
the following U-Tube videos about watersheds and then decide for yourself.
Anatomy of a water shed: https://www.youtube.com/watch?v=f63pwrMXkV4
How are watersheds related to each other? https://www.youtube.com/watch?v=BYwa_0w1jGY
1. Is the saying “We all live downstream” accurate? Why or why not?
2. Would you prefer to live downstream from a farm or a factory? Why?
Water is a valuable resource to all living things.
McHenry County’s clean water seems to be readily available; you just turn on the faucet, right?
Although water does renew itself through the water cycle, the clean water used today will not be
available for use again for generations. Here in McHenry County, the water we use for drinking
and bathing called potable water is pumped from deep aquifers underground. This
groundwater is what we ALL use for everything we do but it is a limited resource.
3. If something is limited, what happens when it gets used up?
4. How could you build up an extra supply of a limited resource?
Water Conservation
When you conserve a resource like water, you use it wisely so that the rate you use it equals the
rate it is replaced.
5. Do you think you use water wisely? Why or why not?
6. What would be the advantage of water conservation efforts?
Water Quality
Industries and even your activities throughout McHenry County have impact on our water
quality. The quality of water in McHenry County affects the quality of all life in McHenry
County (humans, plants, and animals). For example, in recent years Crystal Lake has been closed
and swimming and events cancelled due to high bacteria levels.
7. What are the qualities of clean water?
8. Use the data chart attached to answer these questions:
a) Which location (s) would provide potable water?
b) How would you determine the sample locations (near farm, near factory or
neighborhood well) based on the data?
Now, think about this… who protects your water?
Sampling of Water Quality Test Results
Taken from three locations within a Watershed:
Neighborhood Well, Lake near Factory, and Stream on Farm Property
Maximum
Contaminant
Level (mg/L)*
Sample A
Sample B
Sample C
naturally present in the environment;
as well from animal fecal waste.
5%
0%
6%
5%
Arsenic/
0.01
0.02
0.01
0.00
0.005
0.005
0.001
0.000
0.07
0.00
0.10
0.03
0.2
0.25
0.1
0.1
Contaminant/
Possible Sources*
Total Coliforms (bacteria)/
runoff from orchards, or glass and
electronics production wastes
Benzene/Discharge from factories;
leaching from gas storage tanks and
landfills
2,4-D/
(2,4-Dichlorophenoxyacetic Acid)/
Runoff from herbicide used on row
crops
Cyanide (free form)/
Discharge from steel/metal factories;
discharge from plastic and fertilizer
factories
*Maximum Contaminant Level (MCL) - The highest level of a contaminant that is allowed in drinking water. MCLs are
set as close to maximum contaminant level goals (MCLGs) as feasible using the best available treatment technology and taking
cost into consideration. MCLs are enforceable standards. http://water.epa.gov/drink/contaminants/index.cfm
Other Measurements
Safe Range
Sample A
Sample B
Sample C
pH/
6.5 - 8.5
6.5
6.3
7.2
Clear to bottom
Clear to depth
of 1 foot
Clear to depth
of 0.5 feet
Clear sample
from acid rain or natural erosion
Turbidity (cloudiness)/
from Soil runoff