Water Cycle
Reservoirs,
processes
and Human
Impacts
Student Packet 1 for Matter Cycling Unit
General Biology
Page 1 of 6
Watersheds in Washington
(http://www.ecy.wa.gov/pubs/0801018.pdf)
What is a watershed? Everyone lives in a
watershed. You know your county and city, but
do you know your watershed address?
Unlike states and counties, watersheds have
natural boundaries defined by the shape of the
land and the flow of water. In basic terms, a
watershed, or basin, is all the land that drains to
the same body of water, such as a lake or river.
Smaller watersheds become part of larger
watersheds, as streams feed into rivers, and
rivers flow into oceans. This means wherever
you are and wherever you go, you’re in a
watershed.
What defines a healthy watershed?
Healthy watersheds perform a number of “jobs.”
As water continually cycles through, the
watershed stores and releases water and filters
many pollutants. Trees and plants help anchor
soil and absorb rain and snowmelt, so flooding
and landslides are less severe. Vegetation also
provides shade, keeping water temperatures
cool and stable so fish and other aquatic life can
thrive. In a healthy watershed, water, soil and
air are clean. People, as well as fish and wildlife,
have the water, food, shelter, and other
resources they need to survive.
Causes of Unhealthy Watershed
Increased population and increased pollution
go hand-in-hand. In urban areas, storm water
runoff is the Number 1 water pollution problem.
Developing land typically creates changes in the
natural water patterns of an area. As more
surfaces can’t absorb water, polluted runoff from
rain or snowfall carries oil, fertilizers, pesticides,
trash and pet waste into lakes, streams and the
Puget Sound. Bacteria from failing septic
systems are released into the earth. Our
waters, both on the surface and underground,
become contaminated.
Despite occasional high-snowfall years, such as
the winter of 2007-08, global warming and
climate change are shrinking snow packs and
lengthening droughts. Increasingly, Washington
lacks water where and when it is needed for
communities and the environment. Water cycles
continuously through a watershed, sustaining life
as we know it. As water moves across and
under the land from the highest to lowest point in
a watershed, it picks up everything it touches
along the way. Thus, everybody "lives
downstream." The health of our watersheds is in
danger. Many of our watersheds are unhealthy,
and all are in need of protection.
Diagram Above: A glance at the flow of drinking water for Lynnwood.
Rain at
LHS
North
Creek
Sammamish
River
Lake
Washington
Ballard
Locks
Puget Sound
Page 2 of 6
Your Watershed Address:



If you live near Lynnwood High School, you live in the Lake Washington
Watershed.
If you live on the West side of Lynnwood or certain parts of Seattle, you live in the
Puget Sound Watershed.
Our drinking water in Lynnwood, comes from the Sultan River and ultimately from
the snowmelt in the Cascade Mountains.
Top 5 Specific Problems that Contribute to Water Quality in our Area
(According to Washington State Department of Ecology)
1. Dog poop left in yards or the ground.
2. Washing cars in your driveway or the street.
3. Fertilizing Lawns.
4. Letting Grass Clippings go down storm drains.
5. Failing Septic Tanks
Watershed Analysis Questions: Please answer the following 7 questions.
1.
List the jobs of a healthy watershed.
2. According to the article, what is the number one water quality problem in urban areas?
3.
According to the article above, what are 3 ways that human actions contribute to
pollution in the Lake Washington Watershed?
4. The top 5 specific problems listed above make it harder for water treatment facilities to
provide clean water to drink. What other animals in the Puget Sound might also be
affected by these problems?
Page 3 of 6
5. What is the job of trees, plants and soil in a healthy watershed?
6. North Road is going to be expanded soon, and storm drains are going to be placed
along the street. Which do you think is a better solution:
(1) have storm drains dump water directly into North creek (which eventually flow into
Lake Washington then Puget Sound), or
(2) have storm drains divert runoff first into a wetland pond which will then drain into
North Creek (then Lake Washington and Puget Sound).
Explain your reasoning.
7. The Washington Department of Ecology identified high petroleum (oil) levels at the cross
streets of Filbert Road and Filbert Drive. Predict what might happen to the fish in North
Creek (which is downhill on Filbert Rd. towards Bothell-Everett Highway). From the
article and the top 5 problems listed, what other human actions might hurt the fish in
North Creek from storm water runoff?
STOP HERE!
Page 4 of 6
The Water Cycle
Water is our most recycled resource.
Consider, for example, that the water
you bathed in this morning may have
contained the same molecules of water
that washed over a South Pacific coral
reef a million years ago! The amount of
water on Earth is basically constant, but
the distribution of water changes over
time and space due to a dynamic
process called the water cycle or
hydrologic cycle. The water cycle is
powered by solar energy and gravity.
Warmth from the sun causes
evaporation of water from lakes,
streams and soils and ice and snow.
Solar energy also drives a process
called transpiration—the release and
evaporation of water from tiny pores in
the leaves of plants. Evaporated and
transpired water vapor is stored in the
atmosphere until it condenses and is
pulled by gravity back to earth as rain,
sleet, snow, hail, dew or frost.
Up to 80 percent of this precipitated
water is returned directly to the
atmosphere by evaporation. The rest
may runoff over land and into lakes and
streams or may soak into the ground.
Some of the water that soaks into the
ground stays in the unsaturated zone.
This zone is the rock or soil layer in
which some of the spaces between
particles are filled with air and some are
filled with water. Some of the water in
the unsaturated zone is taken up by
plant roots and returned to the
atmosphere by transpiration. The rest
of the water is pulled deeper into the
ground by gravity, filling all the cracks
and spaces in the underlying layers of
soil, gravel and rock. Water in the
saturated zone is called groundwater.
The top of the saturated zone is the
water table. Water continues to move
underground from areas of high
elevation toward lowland areas. This
movement is generally slow, from a few
feet per day to a few feet per year.
Wherever the water table meets the
land surface a spring may form or
groundwater may seep into to a lake,
stream, wetland or ocean. Once above
ground, the water can evaporate and
return to the atmosphere, and the water
cycle begins again.
Human activities may affect the
quality of water at any point in the cycle.
Air pollution can change the chemical
composition of rain and snow. Runoff
from rainfall and snow melt can pick up
soil, excess plant nutrients, pesticides,
animal wastes, and municipal and
industrial pollutants as it flows over land
and into lakes and streams.
Contaminated runoff can also soak into
the ground and pollute groundwater.
Water percolating through soil and rock
may pick up natural minerals or other
contaminants. Knowledge of the water
cycle can help us understand how water
becomes polluted and how pollution can
be prevented.
(http://pulse.pharmacy.arizona.edu/reso
urces/arsenic/watercycle.pdf)
Page 5 of 6
Water Cycle Questions
Instructions: Please Answer the Following Questions or Draw Diagrams based on water cycle
diagram and water cycle article on page 4.
1. List all the reservoirs of water (places where water is found on earth) from the
diagram above.
2. List 5 processes that move water between reservoirs.
Page 6 of 6
3. What are the two sources that power the water cycle?
4. What are three places groundwater from a water table may move to?
5. Describe 2 human actions that can affect the water cycle.
6. Draw a diagram to show how smoke from a factory can affect your drinking water.