Can You Build a Model Wetland?
Wetlands are important for their ability to clean dirty water by
filtering it. In this investigation, you are going to build a model of
a wetland.
You will be given some materials, including a funnel. You will
select materials for your filtering system, build the model and
conduct 3 trials to get a container of dirty water as clean as
possible. You need to make a diagram of your setup, record
the materials you place in the funnel, and observe and record
what happens when the dirty water is put through your filtering
system.
Can You Build a Model Wetland?
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Can You Build a Model Wetland?
Suggested Grade Span
6–8
Task
Wetlands are important for their ability to clean dirty water by filtering it. In this investigation, you
are going to build a model of a wetland.
You will be given some materials, including a funnel. You will select materials for your filtering
system, build the model and conduct 3 trials to get a container of dirty water as clean as
possible. You need to make a diagram of your setup, record the materials you place in the
funnel, and observe and record what happens when the dirty water is put through your filtering
system.
Big Ideas and Unifying Concepts
Cause and effect
Design
Models
Systems
Life Science Concept
Populations and ecosystems
Science in Personal and Societal Perspectives Concepts
Personal health
Populations, resources and environments
Mathematics Concepts
Data collection, organization and analysis
Diagrams
Measurement - Time
Time Required for the Task
45 to 60 minutes.
Can You Build a Model Wetland?
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Context
This investigation occurred during the middle of a unit on wetland ecosystems. Students had
already researched, discussed and created a bulletin board with drawings, magazine cutouts or
actual objects. They put the symbolic pictures/artifacts on the bulletin board, with a card that
told how it related to the wetland ecosystem. For instance, a magazine cutout of a cradle
showed that wetlands are used to protect the animals’ young, a sponge showed that wetlands
soak up rainfall to prevent flooding, and a Monopoly house showed that animals use the
wetlands for their homes. Students also played a tag game to show how dirt particles get
caught by plant materials and soils and cleaner water emerges. Additionally, students viewed a
Bill Nye video on wetlands.
What the Task Accomplishes
This investigation demonstrates how a wetland works as a filtration system to clean dirty water.
Students practice the ability to make a scientific diagram, observe the cause and effect of the
filtering materials that are placed in filter, record data and draw conclusions based on data
collected. Students use a model to develop their conceptual understanding about systems and
interdependence in ecosystems.
How the Student Will Investigate
I guide the students’ thinking, first by asking them how they get the water they drink. Most of
them say they get water from the faucet. Next, I ask where the water from the faucet comes
from and continue to question them until we have reviewed the water cycle. Then I’ll talk about
a dirty puddle of water I saw on the way to school and ask how that dirty water can become
clean so that the water is reused. That leads to explaining that this investigation will model how
wetlands clean dirty water by filtering.
Students are divided into groups and given a bucket with a variety of natural materials to
choose from. They construct a wetland and record the layers of materials they used to make it.
When students are ready, I move about the room and pour dirty water into their filters. Using a
stopwatch, they record how long it takes for the water to completely drain through the wetland
filter. (If this takes longer than 10 minutes, I suggest they stop at 10 minutes.) They do this two
more times, each time recording the layers of the filter. At the end of the experiment, they use
their observations to write what they learned about how water is cleaned.
Interdisciplinary Links and Extensions
Science/Health
Students can discuss what happens if various pollutants make it through the water-filtering
system and are present in water that we drink. This can be followed up by conducting tests of
water samples from school and home water systems. Students can explore differences
between hard and soft water (such as smell, sudsiness, etc.). Students could add vinegar to the
water and check pH levels (before and after).
Can You Build a Model Wetland?
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Invite the school custodian to talk about legal requirements for how the school monitors water
quality. Have a hiker or military person explain how s/he can purify water while hiking on the
trail.
Social Studies
Students can research and create a map of their state, showing where the wetlands can be
found in their community and/or state. Students can research laws protecting wetlands in their
regions. Students can visit local wetlands or local water filtration systems.
Language Arts
Students can write and illustrate a short story or poem about what it would be like to be one of
the dirt particles as it travels from the jar, gets caught going through the filter and watches the
water coming out clean. Students can write and illustrate the procedure for how water is filtered
in a wetland or in a home water-filtering system.
Movement/Music/Physical Education
Students can create a play about, or pantomime to music, what happens to soil particles and
water when they travel through the filtering system.
Teaching Tips and Guiding Questions
As the students put various layers in their funnels, ask them why they are putting the materials
in that order.
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Can you explain your reason for putting materials in this order?
Can you explain your reason for selecting these materials?
What observations did you make during the first trial?
What changes did you make from experiment one to two? from two to three?
Is the water getting cleaner or dirtier? Why do you think that is happening? Where is the
dirt going?
Can you describe how the water is passing through the filter? Why is it taking so long for all
the water to come through the filter?
Is there more, less or the same amount of water coming through each time? How could
you determine this?
Does the order of the materials in the funnel affect how clean the water is? How could you
determine this?
How is this model like a real wetland? What have you learned about wetlands from your
model?
What have you learned about how water is cleaned?
What would happen if the water was polluted? Would the wetland filter out all of the
harmful pollutants?
Can You Build a Model Wetland?
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Concepts to be Assessed
(Unifying concepts/big ideas and science concepts to be assessed using the Science
Exemplars Rubric under the criterion: Science Concepts and Related Content)
Science in Personal and Societal Perspectives – Populations, Resources and
Environments; Personal Health: Students look for evidence and describe how human actions
can cause changes in vegetation, ecosystems and/or entire landscapes. Students understand
conservation and why it is needed.
Life Science – Populations and Ecosystems: Students see that human activities have an
impact on natural systems and that changing human behaviors can lessen the impact on
ecosystems.
Scientific Method: Students see that how a model works after changes are made to it may
suggest how the real thing would work if the same thing were done to it. Students understand
that choosing a useful model (not too simple/not too complex) to explore concepts encourages
insightful and creative thinking in science, mathematics and engineering (models). Students
observe and explain cause-effect relationships with some justification, using data and prior
knowledge, when variables are controlled.
Mathematics: Students use precise measurements (time) and diagrams. Students collect,
organize and analyze data appropriately.
Skills to be Developed
(Science process skills to be assessed using the Science Exemplars Rubric under the criteria:
Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data)
Scientific Method: Predicting/hypothesizing, planning/conducting investigations, observing,
manipulating tools, drawing diagrams, collecting/recording data, drawing conclusions based
upon results and communicating what was learned.
Other Science Standards and Concepts Addressed
Scientific Method: Students describe, predict, investigate and explain phenomena.
Scientific Theory: Students look for evidence that explains why things happen and modify
explanations when new observations are made.
Life Science – Populations and Ecosystems: Students understand that human actions can
cause changes in vegetation, ecosystems and/or entire landscapes. Students observe that the
number of organisms an ecosystem can support depends on the resources available and on
abiotic factors, such as quality of light and water, range of temperatures and soil composition.
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Communication: Students use verbal and nonverbal skills to express themselves effectively.
Science in Personal and Societal Perspectives – Personal Health: Students observe that
natural environments may contain substances that are harmful to human beings and that
maintaining environmental health involves establishing or monitoring quality standards related
to water, soil and air.
Suggested Materials
We used clear plastic soda bottles, cut in half. A few weeks before doing the investigation, you
might want to begin collecting some two-liter bottles. An easy way to cut the bottles is to place
each bottle inside a box lid (to hold it steady for an even cut) and turn it slowly while holding a
sharp utility knife in place. The top will be the funnel; the bottom will be the container that the
water drains into. (An excellent resource book for using plastic soda bottles for science
investigations is Bottle Biology, by Paul Williams, Mrill Ingram and Amy Kelley, published by
Kendall Hunt.)
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A Mason jar half-filled with soil and half-filled with water
3 coffee filters so the materials don’t wash out the hole in the soda bottle
A stopwatch
Sphagnum moss
Sand
Rocks of different sizes
Gravel, both fine and coarse
Newspapers to cover the desks (large plastic garbage bags also work well for this)
A plastic bucket to put all the materials in to give to students
Optional: You can also add leaves, food coloring, soap or oil, although, I did not. You could also
add vinegar and check pH before and after filtering the water.
Possible Solutions
Students could put the materials from finest to roughest or vice versa in the filter. Materials that
are randomly thrown into the funnels may begin to settle into layers, rough to fine, naturally. As
students complete the second and third trials, the water should become cleaner. The diagram
should label materials used in the filtering system. Times should be recorded for each trial and
conclusions stated, based on observations.
Task-Specific Assessment Notes
Novice
This student’s solution is incomplete. It appears that only one trial was completed, as one time
is recorded. A diagram is included but lacks appropriate labels. The student does not record
any materials used to clean the filter. There is no explanation of what was observed.
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Apprentice
Sample #1
This student’s solution is lacking in detail, although the task is completed. Only one time is
recorded, though three trials are conducted. The student includes three labeled drawings. It
appears that materials were changed each time, but no changes made between experiments
are recorded, other than the labeling. The student attempts to demonstrate some understanding
of the water cycle in the explanation, but the explanations are confusing. Some results are
summarized, but conclusions are not supported by data or reasoning using scientific or design
concepts.
Sample #2
This student’s solution is lacking in detail, although the task is completed. Times are recorded
for three trials, but they are not precise (all times are the same). The student includes three
labeled drawings. It appears that materials were changed each time, but no changes made
between experiments are recorded or explained. Some results are summarized, but
conclusions are not supported by data or reasoning using scientific or design concepts.
Practitioner
This student’s solution is complete. Precise times are recorded for three trials. The student
includes three labeled drawings. Only general changes between experiments are recorded
(e.g., “everything”). Results are summarized, and conclusions are supported by specific data
from observations (e.g., “mostly gets cleaned by moss, then vermiculite cleans second most”).
The explanation also discusses the water cycle.
Expert
This student’s solution is complete. Precise times are recorded for three trials. The student
includes three labeled drawings. Materials were changed each time, and changes made
between experiments are recorded and explained (e.g., “Moss between layers to absorb
more”). Results are summarized, and conclusions are supported by specific data from
observations (e.g., “vermiculite sucked up the water,” and “wetland moss cleaned the water the
best”). There is an additional diagram of the water cycle, which is clearly labeled using
appropriate scientific language.
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Novice
Can You Build a Model Wetland?
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Apprentice
Can You Build a Model Wetland?
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Apprentice
Can You Build a Model Wetland?
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Apprentice
Can You Build a Model Wetland?
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Apprentice
Can You Build a Model Wetland?
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Apprentice
Can You Build a Model Wetland?
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Apprentice
Can You Build a Model Wetland?
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Practitioner
Can You Build a Model Wetland?
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Practitioner
Can You Build a Model Wetland?
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Practitioner
Can You Build a Model Wetland?
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Expert
Can You Build a Model Wetland?
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Expert
Can You Build a Model Wetland?
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Expert
Can You Build a Model Wetland?
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