Reasoning Tools for Understanding Water Systems
Watersheds & Surface Water
Contents
Agenda for the Day ....................................................................................................................................... 2
Scientific Practices: Scientific Models and Model-Based Reasoning: .......................................................... 3
The Upper Anchor for Watersheds (Surface Water) .................................................................................... 5
Learning Progression Levels for Watersheds ................................................................................................ 6
Examples of Student Responses to Schoolyard Map FA ............................................................................... 9
Student Learning and Instructional Activity Table: Watersheds and Surface Water ................................. 11
Watersheds & Surface Water Activity Sequence Overview ....................................................................... 12
Student Learning and Instructional Activities (Watersheds and Surface Water Systems) Complete .... 13
Scientific Practices and Instructional Activities: Watersheds & Surface Water ..................................... 14
Teacher Practices and Instructional Activities: Watersheds and Surface Water.................................... 16
Watersheds & Surface Water Activities...................................................................................................... 18
Watershed Models.................................................................................................................................. 21
Tracing a Watershed ............................................................................................................................... 38
Exploring Runoff & Surface Type ............................................................................................................ 45
Color Me a Watershed ............................................................................................................................ 48
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Reasoning Tools for Understanding Water Systems
Agenda for the Day
Day #2 Watersheds*
8:30
Loose ends from Day #1
8:45
Scientific Practices: Models and Modeling
9:15
9:45
Introduction to Watersheds
 Upper anchor for watersheds and surface water
 Student thinking about watersheds
Break
10:00 Formative Assessments for Surface Water
 School Map
 Wash Trash
11:00 Introduce Tools for Reasoning
 Pathways Tool
 Drivers and Constraints
11:45 Lunch
12:30 Watershed Models
1:30
Tracing Watersheds
2:15
Break
2:30
Runoff Activity
3:15
Color Me a Watershed
4:00
Tucson Water Story (if time is available)
4:30
Done
Homework Assignment for Day 3:
Ready Set Science: Chapter 5 Talk and Argument
*All times are estimates
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Reasoning Tools for Understanding Water Systems
Scientific Practices: Scientific Models and Model-Based Reasoning:
A scientific model is an abstract, simplified representation of a system or phenomenon that
makes the central features of the system or phenomenon explicit and visible, and that can be
used to generate explanations and predictions (Harrison and Treagust, 2000). Examples of types
of scientific models include conceptual models (e.g., Mendel’s simple dominance of heredity
model), diagrams (e.g., water cycle diagram), mathematical models (e.g., Malthusian
population growth model), and physical models (e.g., stream water table).
Working with scientific models involves constructing and using models, as well as evaluating
and revising them. Schwarz et al. (2009) operationalize modeling practices to include:
 Students can construct models consistent with prior evidence and theories to illustrate,
explain or predict phenomena
 Students can use models to illustrate, explain, and predict phenomena
 Students can compare and evaluate the ability of different models to accurately represent
and account for patterns in phenomena, and to predict new phenomena
 Students can revise models to increase their explanatory and predictive power, taking into
account additional evidence or aspects of a phenomenon.
Model-based reasoning involves all of these practices. Environmental science literate citizens
should be able to engage in these modeling practices in order to understand the science of
environmental issues, predict likely outcomes of different courses of action, and inform their
decisions about what personal actions to take.
It is important to clarify that not all representations are models. Models are specialized
representations that embody aspects of mechanism, causality and function to illustrate, explain
and predict phenomena. In other words, models must embody information about how and why
a system or phenomenon works the way it does.
Interestingly though, it is possible for some representations to serve as models for some
people, but not for others. Consider the water cycle diagram. Young students memorize the
water cycle diagram, dutifully indicating that water evaporates into the sky, condenses in
clouds, precipitates to the ground, and then returns to the sky in a never-ending cycle. For
young students, however, this diagram is often just a representation --- a story of water going
from one place to the next through named processes. The water cycle only becomes a model
when one considers the causality and mechanisms involved with water moving. What causes
water to move from place to place? In other words, what’s the driving force for water moving?
Sometimes it is gravity, sometimes, heat energy, sometimes pressure. The word gravity
generally doesn’t appear in most diagrams of the water cycle. Yet it is there as an implicit
understanding for individuals who use the water cycle diagram as a model for predicting and
explaining what happens to water in the environment.
Further, while young students view the water cycle as having a definite order – rain to ground
to evaporation and back again, more sophisticated model-based reasoners understand that at
any point in the cycle, water could go to different places next – depending on constraining
factors such as topography, permeability, or relative humidity. Being able to reason about
multiple diverse possibilities using a model is another characteristic that distinguishes modelbased reasoning from merely reading a representation. In short, what makes something a
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Reasoning Tools for Understanding Water Systems
model instead of a representation is sometimes about what a person brings to the model from
their own understanding about implicit, rather than explicit, elements of causality, mechanism
and function of the system or phenomenon that is being represented.
Ideas about modeling practices described above are from:
Schwarz, C. V., Reiser, B. J., Davis, E. A., Kenyon, L., Achér, A., Fortus, D., et al. (2009).
Developing a learning progression for scientific modeling: Making scientific modeling
accessible and meaningful for learners. Journal of Research in Science Teaching, 46, 632654.
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Reasoning Tools for Understanding Water Systems
The Upper Anchor for Watersheds (Surface Water)
Structure of Watersheds: Watersheds (surface water systems) are connected to the
atmospheric water system and the groundwater system. Water can exist on the surface in
liquid and frozen states.
 Macroscopic Scale: Water that falls on the land either runs off over the surface
watershed, infiltrates into the groundwater system, or evaporates into the atmosphere.
Waters running off across land, as well as water in lakes, ponds, river, streams, creeks
and oceans are all part of the surface water system.
 Large (Landscape) Scale: A watershed is an area of land where all of the surface water
that drains off goes to the same place, often a body of water such as a river, lake, or
ocean. The high point between two watersheds is the watershed boundary or a water
divide. The watershed boundary does not necessarily have to be a noticeable ridgeline.
In relatively flat landscapes, a watershed boundary could be a very slight rise in the land
not noticeable to the eye. Watersheds can be nested within one another. For example,
tributary watersheds are nested within larger river watersheds. Tributary parts of
watersheds are higher in elevation than the downstream sections of the larger river
watershed systems they belong to.
Processes in Watersheds: Water moves in and out of as well as through the surface water
system. Surface water flow is called runoff. These processes can be described at different
scales.
 Macroscopic and Landscape Scales: Water enters the surface water system from the
atmosphere through condensation and precipitation. Water also enters the surface
water system through discharge from the groundwater into springs, marshes, streams,
rivers, lakes, ponds, etc.
 Microscopic Scale: Water moves between the surface and atmospheric systems by
changing state. During evaporation, water in the liquid state changes to the gas state;
during precipitation water in the gas state changes to the liquid state.
Scientific Principles: Water moves through watersheds according to scientific principles
 Drivers: Water moves downhill due to gravity. Energy is required to move water uphill.
 Constraints: The rate and volume of runoff (discharge) in a watershed is affected by
o Topography and slope – Constrains direction of flow and rate of flow
o Surface Type – Constrains volume of runoff and infiltration. Includes:
 Permeability: Water runs off more quickly from impermeable surfaces;
less volume infiltrates.
 Vegetated cover: Water runs off more slowly from vegetated surfaces
and has more time to infiltrate.
Representations: Watersheds are usually represented on maps. Topography can be
represented by elevation contours. However, using principles of water moving in surface water
systems, relative elevations can be inferred from maps.
Dependency & Human Agency: Watersheds and surface features of the Earth change naturally.
Water erodes Earth materials from one location and transports and deposits them in other
locations. Natural changes in weather and climate can also affect the rate and volume of runoff
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Reasoning Tools for Understanding Water Systems
and infiltration as well as the water quality within a watershed. Human activities (e.g., building
or removing dams, paving surfaces, removing vegetation, changing the composition of the
atmosphere) can also change the rate and volume of runoff, volume of infiltration into the
groundwater system, and quality of water within a watershed.
Learning Progression Levels for Watersheds
Level 4: Model-Based Accounts
Level 4 accounts of watershed fit the upper anchor described above. Level 4 accounts use
drivers and constraints to explain how and why.
Level 3: Incomplete School Science Accounts
At level 3, accounts are characterized by the retelling of stories or parts of stories about the
water cycle usually learned in school. These stories put events in order, often include multiple
pathways for water, and provide scientific names of processes that move and mix water at the
macroscopic scale. However, these accounts are often incomplete, with steps missing or errors
in tracing water and substances in water across systems. Furthermore, they do not include
driving forces or constraining factors when tracing water or substances in water.
Structure & Systems: Level 3 accounts are often characterized by school science stories and
rules that describe systems without explicitly addressing driving forces and constraining factors.
For example, students at Level 3 may indicate that a watershed boundary is always a hill or
ridge, without understanding that changes in elevation that constrain movement of water can
often be slight slopes. Level 3 accounts indicate that surface water and groundwater systems
are connected. Interestingly, Level 3 accounts rarely identify groundwater as a source of river
water unless specifically probed about why there is water in rivers even if it hasn’t rained
recently.
Scale: Level 3 accounts trace water from microscopic to landscape scales. They trace water
across large distances, and can also talk about molecules, without describing processes,
movements or changes at the atomic-molecular scale.
Scientific Principles: Level 3 accounts explain phenomena by putting events in order to tell a
story about what happens. For example, they trace water that evaporates from a puddle into
water vapor in the atmosphere, then indicate that water condenses into a cloud, and
precipitates back to the ground. These accounts name specific processes that move water and
substances in water, such as infiltration, evaporation, condensation, and dissolution. However,
level 3 accounts do not identify driving forces such as gravity or pressure, which move water
and substances, or factors, such as permeability or topography, that constrain the pathways
along which water and substances move. For example, when tracing water from a puddle, a
school science story might identify that the water could infiltrate, evaporate, or runoff without
considering the ways that permeability or topography might limit infiltration or runoff. As a
result, at level 3, explanations and predictions suggest that water would be equally likely to
follow any of a number of pathways and do not use generalized models to analyze why, given
the variables present, water might be more likely to flow along one pathway than another.
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Reasoning Tools for Understanding Water Systems
Representations: Level 3 accounts can trace water in three dimensions using 2-dimensional
maps. However, they do not consider the implications of constraining factors on pathways they
identify from representations.
Dependency & Human Agency: Level 3 accounts recognize that human systems are part of
environmental systems and that human actions have impacts on environmental systems.
Level 2: Force-Dynamic Accounts with Mechanisms
Level 2 accounts show an expanded awareness of and experience with the physical world.
These accounts provide more sophisticated force-dynamic explanations and predictions about
water. Most significantly, mechanisms to move water or change water are included.
Structure & Systems: Level 2 accounts specifically note that the water flows from one place to
another. They also suggest that students have a broader view of the landscape. For example,
one Level 2 response about how water gets into a river states that, “If enough water forms it
can form a little stream of some kind and the stream will go down into the river” (ES) This
response indicates awareness of a hierarchy of river sizes.
Scale: Level 2 accounts are aware that at the macroscopic scale, water will run downhill.
However, Level 2 accounts generally do not apply this reasoning at the landscape scale.
Scientific Principles: Level 2 accounts rely on natural tendencies of water, such as water
spreads, drifts, travels, or flows to places that are connected or nearby. Accounts may also
reference informal rules for reasoning about water pathways, such as water flows from larger
bodies of water to smaller bodies of water. These accounts rely heavily on actors or agents to
moves water, such as clouds sucking up water.
Representations: When referring to maps, Level 2 accounts make explicit connections between
representations of rivers on maps and water flowing in rivers, but do not constrain which
direction water moves.
Dependency & Human Agency: Level 2 accounts recognize connections between natural and
human-engineered systems, but do not rely on humans as the source or cause of water
movements. They also recognize that humans benefit or are impacted by movements of water
and substances in water if human-engineered systems and structures are in the right place at
the right time. For example, water gets into a bathtub if the ceiling leaks and the rain gets
inside or if a window is open.
Level 1: Force-Dynamic Accounts
Level 1 accounts portray a human-centric focus and force-dynamic reasoning. Water is
identified in visible, familiar contexts, such as in puddles, rivers or streams, lakes, oceans, and in
faucets, toilets, and bathtubs. Furthermore, these accounts focus on human uses of and
experiences with water. At this level, accounts portray water as part of the everyday world and
as something that people can use and do things to in order to move or change it.
Structure & Systems: Level 1 accounts depict visible water in isolated locations, unconnected to
water in other locations. These accounts imply that water that is not visible is “out of sight, out
of mind”—no longer worthy of attention. The water in the puddle, for example, dries up and is
gone rather than moving to another location.
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Reasoning Tools for Understanding Water Systems
Scale: Level 1 accounts focus awareness on macroscopic, immediately observable scale. They
do not acknowledge water in hidden or invisible locations.
Scientific Principles: Level 1 accounts indicate that water in rivers is moving, but they do not
identify where the water in the river comes from or where it is going. Level 1 ideas about how
water gets into a river often suggest that rain falls into the river or humans put water in a river,
but they do not identify other possible natural sources such as runoff, snowmelt, or
groundwater.
Representations: Level 1 accounts do not necessarily connect representations of watersheds to
the physical world. They may note that the lines labeled as rivers are connected to other lines
on the map, but do not indicate that the water in one river moves to or from another river.
These accounts also say that water flows down the paper or that water always goes south.
Dependency & Human Agency: These accounts portray humans as the sources and movers of
water in watersheds.
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Reasoning Tools for Understanding Water Systems
Examples of Student Responses to Schoolyard Map FA
1
2
3
If you were looking from side instead of
above, what would shape of land be like?
F. We don’t know what the ground is like
with this diagram.
Which direction is School Creek flowing?
D. The school creek would be contained at
a lower elevation than the surrounding
areas. As far as the rest of the crosssection, there is no further evidence of
elevation change.
D. Well, I think that it stays the same, and
then it gets to the creek so it dips then
goes back to normal.
You can’t tell. The map gives no contour
lines or elevation markers that would
show an elevation slope. Water runs
downhill and I do not see any evidence of
direction or slope.
You can’t tell. Well, I can’t see any way
that the water is moving North or South.
Level
Notes on levels or foci for
instruction
You can’t tell. The map doesn’t show the
way the current is flowing.
4
A. I looked at the pitcher above and it gave N. North because it showed an arrow with
you a line and I looked at the answers and an N on it so I think that meant North.
overlayed it.
5
D. I think D because it has a dip where the
creek would be.
You can’t tell from the map because it is
an over hed view.
6
A. Because if you look at it sideways it is
straight but it curves up a little.
S. Because North is up and South is down.
7
D. The “dry” land would have to be at an
elevation greater than the creek in order
for the water not to spread out uniformly.
You can’t tell. Depends on North to South
elevation change and no information
about this is given.
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Reasoning Tools for Understanding Water Systems
8
If you were looking from side instead of
above, what would shape of land be like?
F. From above it looks flat.
9
Which direction is School Creek flowing?
Level
Notes on levels or foci for
instruction
You can’t tell. On the map it can’t tell.
D. Because the river needs to be lower
than the school or the H2O would flow
into school. Middle flat due to playing
field.
10 C. If seen on the same level it would just
look like it’s directly across.
You can’t tell. There is no elevation or
other visuals to give you a hint of “down
hill.” Gravity flow is down hill.
11 D. So when you walk from the school
across this field its flat but when you get
to the creek it sinks into the ground.
You can’t tell. The picture doesn’t show if
it is running of a mountain or hill in the
north or south.
12 F. I think the stream could be flowing
either way. So there is no way to tell
where it is flowing so you don’t know if it
is on a hill or not.
You can’t tell. It could be flowing either
way.
S. From my basic understanding of how
water flows.
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Reasoning Tools for Understanding Water Systems
Student Learning and Instructional Activity Table: Watersheds and Surface Water
What students need to work on
(Foci for instruction)
Watershed Models &
Tracing Watersheds
Exploring Runoff
Color Me a Watershed
Structure &
Systems:
Scale
Scientific
Principles
Representations
Dependency &
Human Agency
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Reasoning Tools for Understanding Water Systems
Watersheds & Surface Water Activity Sequence Overview
Activity/Description
Learning Goals – Practices fused
with content
Formative
Assessments
Drivers &
Constraints
Representations
Tools
Watershed Models
Students will
- Investigate watersheds and identify
components of surface water
system
- Use and interpret 3D & 2D models
of watersheds to trace water
- Explain and predict how and why
water moves in the surface system
(watersheds) at landscape scales.
Students will
- Use and interpret 2D models (maps)
of watersheds to trace water to
trace water through watersheds.
- Explain and predict how and why
water moves in the surface system
at landscape scales.
- Runoff
- School Map
- Gravity pulls water
downhill
- Topography
constrains path of
water
3-D model of
watershed using a
tarp moving to 2-D
model (maps) of
watershed
- Pathways tool to trace
where water goes.
- Drivers & Constraints
tool to reason about
how topography
shapes the pathway of
the land.
- Runoff
- School Map
- Gravity pulls water
downhill
- Topography
constrains path of
water
Maps of
watersheds
- Pathways tool to trace
water in a watershed.
- Drivers and
Constraints tool to
reason about
topography using a
map representation.
- Gravity pulls water
down
- Vegetation and
permeability of a
surface constrains
runoff
Physical models of
watersheds and
surface types
-
- Gravity pulls water
down
- Topography
constrains the path
of water
- Vegetation and
permeability of a
surface constrains
runoff
Maps of
watersheds and
surface type
- Pathways tool to trace
water
- Drivers and
Constraints Tool to
predict and explain
pathways
Students explore a 3D
model of watersheds.
Tracing a Watershed
Students explore
watersheds using maps.
Exploring Runoff &
Surface Type
Students explore how
different surface types
affect runoff.
Color Me a Watershed
Students compare maps
of a watershed at three
different times to explore
how changes in land use
affect runoff
Students will
- Investigate the drivers and
constraints of runoff and
infiltration.
- Explain and predict the relationship
between surface type, permeability,
and runoff volume
Students will
- Use and interpret 2D models (maps)
of watersheds to trace water to
trace water through watersheds.
- Use models of the relationship
between surface type and runoff to
explain and predict how changes in
land use affect volume of water in a
watershed.
- Runoff
- School Map
Drivers and
Constraints tool to
reason about
surface types
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Reasoning Tools for Understanding Water Systems
Student Learning and Instructional Activities (Watersheds and Surface Water Systems) Complete
Structure &
Systems:
What students need to work on
(Foci for instruction)
Watershed Models &
Tracing Watersheds
Seeing watersheds as an area of land, not a
body of water. (L2 to L3)
Using maps and models to
identify components of
watersheds, including
watershed divides (L2 to L3
and L3 to L4)
Tracing water along multiple steps and
multiple pathways (L2 to L3)
Identifying watershed boundaries, even in
areas with moderate or low topography (L3
to L4)
Scale
Moving to landscape scale (L2 to L3)
Scientific
Principles
Representations
Dependency &
Human Agency
Moving from informal rules towards
considering drivers (gravity) and constraints
(topography, surface type) (L3 to L4)
Moving from interpreting 3D to 2D
representations(L2 to L3)
Interpreting drivers and constraints from
representations (L3 to L4)
Recognizing how surface water and human
actions are connected. (L2 to L3)
Recognizing how topography & surface type
influences human connections (L3 to L4)
Color Me a Watershed
Using models to see that
watersheds have different
surface types (L2 to L3)
Using Pathways tool to trace
water through multiple steps
and along multiple pathways
(L2 to L3)
Using Pathways tool to trace
water pathways (L2 to L3)
Reading 3D models and 2D
maps of landscapes (L2 to L3
and L3 to L4)
Reading models and maps
Moving from force-dynamics to rules for
interpreting maps(L2 to L3)
Exploring Runoff
Using D&C tool to explore
drivers and constraints that
influence on water pathways
(L2 to L3 and L3 to L4)
Writing Accounts (Explaining
& Predicting) of water
pathways (L2 to L3 to L4)
Using Models: Comparing 3D
models to 2D map
representations (L2 to L3)
Using D&C tool to consider
topography and surface type
on pathways in
representations (L3 to L4)
Exploring impacts at
different places in
watersheds. (L2 to L3 to L4)
Reading maps of landscapes
(L2 to L3 and L3 to L4)
Investigating: Investigating
surface types and runoff (L2
to L3 and L3 to L4)
Using D&C tool to reason
about surface type on water
pathways and runoff volume
(L2 to L3 and L3 to L4)
Writing Accounts (Explaining
& Predicting) of water
pathways (L2 to L3 to L4)
Using D&C tool to consider
relationship between
topography and surface type
to runoff direction and
volume (L2 to L3 and L3 to
L4)
Writing Accounts (Explaining
& Predicting) of water
pathways (L2 to L3 to L4)
Using Models: Map
representations (L2 to L3 to
L4)
Investigating & Analyzing:
Impacts of changing surface
type on runoff (L2 to L3 to
L4)
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Reasoning Tools for Understanding Water Systems
Practices
Scientific Practices and Instructional Activities: Watersheds & Surface Water
What Students Need to
Work On (Foci for
Instruction)
Using Models Developing understanding of
& facility w/both 3D & 2D
representations.
Investigating, Using first hand-experiences
Analyzing,
w/real world &/or maps &
Interpreting
models to explore, analyze &
Data
interpret how water flows
through connected systems.
Constructing Moving from force-dynamics
Explanations & informal rules to
considering drivers (gravity)
& constraints (topography &
surface types) to explain
movement of water.
Arguments
Developing, defending &
From
evaluating arguments &
Evidence (&
explanations using
Social
experience, evidence &
Construction) scientific principles in social
context (i.e., peer to peer).
Watershed Models &
Tracing Watersheds
Exploring Runoff
Color Me a
Watershed
Using maps and models to
identify components of a
watershed.
Analyzing map data to build
a watershed model.
Analyzing map data to
determine watershed
pathways.
Using D&C Tool to explain
gravity and topographic
influence on water
pathways.
Using models to see that
watersheds have
different surface types.
Investigating and
analyzing surface types,
runoff & infiltration.
Using D&C Tool to
explain how/why
surface type impacts
surface water pathways
& runoff volume.
Using maps to trace
water along multiple
pathways.
Investigating &
analyzing longitudinal
data related to
development &
runoff.
Using D&C Tool to
consider how
topography & surface
type relate to runoff
direction & volume.
Co-constructing watershed
model from map
w/classmates.
Developing, defending &
evaluating watershed
pathways on Pathways &
D&C Tools.
Developing, defending
and evaluating
pathways from surface
water on D&C Tool.
Developing and
defending an
argument that
explains the data.
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Cross-Cutting Concepts
Reasoning Tools for Understanding Water Systems
Scale,
Proportion &
Quantity
What Students Need to
Work On (Foci for
Instruction)
Moving from macroscopic to
landscape scale
understanding.
Systems &
System
Models
Seeing watersheds as an
area of land, not a body of
water.
Flow &
Conservation
of Matter
Stability &
Change
Watershed Models &
Tracing Watersheds
Exploring Runoff
Color Me a
Watershed
Being able to translate 3D
models to 2D maps & vice
versa.
Understanding role of
surface type in
proportion of runoff
versus infiltration.
Developing
understanding of
surface water system &
connection to
groundwater system.
Using models to trace
surface water.
Connecting
macroscopic &
landscape scale data.
Developing understanding
of what a watershed is and
how it works through
experience with model and
maps.
Tracing water along multiple Using Pathways Tool to
steps and multiple pathways. trace water pathways in
watersheds.
Recognizing how surface
water and human actions
are connected.
Recognizing how topography
& surface type influences
human connections
Exploring impacts (e.g., oil
spill) at different places in
watersheds.
Developing
understanding of
watershed processes
in different
conditions.
Using multiple maps
to compare water
flow in different
conditions.
Investigating impacts
of changing surface
on runoff versus
infiltration
proportions.
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Reasoning Tools for Understanding Water Systems
Teacher Practices and Instructional Activities: Watersheds and Surface Water
Formative Assessment
Watershed Models & Tracing
Exploring Runoff
Color Me a Watershed
Watersheds
Draw a Watershed Use this formative assessment to identify students’ ideas about what a watershed is
before they begin to build the watershed model. Some students may think a watershed is a building
where water is kept. You may want to use this formative assessment again later in the unit and allow
students to compare their original ideas with their understanding after studying watersheds.
Wash Trash Use this formative assessment to identify students’ ideas about how to use a large-scale map
showing waterways to identify which way water (and things carried by water) flow. The Watershed
Models, Tracing Watersheds, and Color me a Watershed activities can help students begin to understand
how to make sense of maps to trace water. The Student Learning and Instructional Activities table on p.
13 provides ideas for using the activities to support students to develop understandings related to this
formative assessment. Further suggestions are also provided in the formative assessment teacher
materials.
Tools for Reasoning
School Map Use this formative assessment to identify students’ ideas about how to read topography and
water flow direction on a small-scale map. This formative assessment can help you understand if your
students are seeing that the map represents a 3-dimensional space and how they are interpreting those
3-dimensions from the 2-dimensional map. This formative assessment is similar to Wash Trash, only at a
different scale. See the Student Learning and Instructional Activities table on p. 13 as well as the
formative assessment teacher materials for suggestions to support students who perform at different
learning progression levels for this formative assessment.
Use the Pathways Tool to help
Use the Drivers & Constraints Use the Pathways Tool to scaffold
students reason about what are
Tool to help students explain
interpreting two-dimensional
reasonable pathways for water in the pattern they find in what
representation of threea watershed (including surface
happens to water that falls on dimensional space and tracing
water pathways and other
different surface types.
water in the stream. The idea is to
pathways such as infiltration,
Students can also use this tool help students interpret which
evaporation, irrigation, etc.)
to explain why (flash) floods
direction runoff flows.
could occur in desert and/or
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Reasoning Tools for Understanding Water Systems
Supporting Explanation
Social Construction of
Understanding
Use the Drivers & Constraints
developed areas.
Use the Drivers and Constraints
Tool to help students reason
Tool to support students in thinking
about how and why water moves
about whether water will infiltrate
along the pathways it does in a
or runoff from the land the surface.
watershed.
Use the Drivers & Constraints Tool and application questions in activities (e.g., oil spill question in
Watershed Model activities, why people in deserts need to worry about flash flood question in runoff
activity) to press students to not just DESCRIBE WHAT will happen, but to also EXPLAIN HOW AND WHY
events and processes in water systems happen.
Use participatory and collaborative teaching strategies to engage students in co-constructing their
understanding.
 When you use formative assessment at the beginning of a unit or lesson, allow students to share
their different ideas about “what, how and why” questions, but do not give the correct answers at
this point. Write down different students’ ideas in a public place so they can be revisited throughout
the unit (e.g., during investigations and further development of explanations).
 During investigations and other activities, have students work in small groups first to share their
ideas and construct their explanations. Students may feel more comfortable sharing ideas if, initially,
they are not asked to share in front of the whole class. Working in small groups, students also have
the opportunity to learn from each other, and not just from the teacher. They also have the
opportunity to question each other’s ideas.
 After students have worked in small groups, provide opportunities for groups to share their ideas
and explanations with the whole class (e.g., completed tools, written explanations for application
questions). If possible, use a document camera or other way to display groups’ responses so they can
be seen by the whole class. Rather than evaluating students’ answers as the teacher, ask the students
to consider and evaluate each others’ ideas and explanations. Do they agree or disagree? Why?
Encourage students to be respectful when they disagree.
 Scientific argumentation is a central practice that scientists engage in every day. Providing
opportunities for students to engage in scientific argumentation with peers supports development of
a core scientific practice. Students learn that science is not just a body of facts to be learned from a
textbook or a teacher. Rather, science is a process of learning about the world that scientists engage
in together as a collaborative and critical community.
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Reasoning Tools for Understanding Water Systems
Watersheds & Surface Water Activities
Summary of Activities
Activity #1: Watershed Models:
Students build a three-dimensional model of the local watershed and trace water through the
watershed.
Activity #2: Tracing a Watershed
Students explore a map of their own watershed. Students explore a map showing their own
watershed. They identify tributaries and watershed boundaries for their watershed. Students
also use the map to identify smaller watersheds that are nested within their own watershed,
and/or larger watersheds that their own watershed is nested within. Students will deepen their
understanding of the concept of a watershed, of how watersheds are interconnected, and of
how the place where they live is part of a specific watershed.
Activity #3: Exploring Runoff and Surface Type
Students compare three surface types to explore how surface type affects runoff infiltration.
Activity #4: Color Me a Watershed:
Students compare three maps to see how development can affect a watershed.
Learning Goals
In these activities, students explore the following questions.
1. What is a watershed?
2. Where does the water flow in my watershed?
3. When does water run off? (or, why are there flash floods in urban and desert areas?)
4. How does human activity impact surface water runoff in watersheds?
Practices fused with content
Students will
 Investigate watersheds and identify components of surface water system
 Use and interpret 3D & 2D models of watersheds to trace water
 Explain and predict how and why water moves in the surface system (watersheds) at
landscape scales
 Investigate the drivers and constraints of runoff and infiltration.
 Explain and predict the relationship between surface type, permeability, and runoff
volume
 Use models of the relationship between surface type and runoff to explain and predict
how changes in land use affect volume of water in a watershed.
 Construct and evaluate arguments from evidence and communicate information about
surface water pathways.
Cross-Cutting Themes
1. Patterns in surface water flow.
2. Causal relationships between surface water pathways and topography.
3. Components of the surface water systems.
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Reasoning Tools for Understanding Water Systems
Elements of Accounts in the Learning Progression
1. Structure of Systems: Structure of the watersheds and the surface water system
2. Scale: Landscape
3. Scientific Principles:
Drivers:
Gravity -Water flows down in elevation due to gravity.
Constraints:
Topography – water will run off from high elevation to low elevation
Surface Type – How much water runs off is affected by
 Permeability – Water runs off impermeable surfaces and infiltrates permeable
surfaces
 Vegetation cover – Water runs off slower on vegetated surfaces and infiltrates
more. More water runs off unvegetated surfaces.
4. Representations:
3-D models of watersheds
2-D map representations of watersheds
5. Human Dependency and Change: Topography and surface type constrains where water
flows. Humans depend on water fresh water that enters watersheds as rain. Our actions
can change how much fresh water is available and how it is distributed across the
landscape. For example, humans change where and how water flows in a watershed
when they change topography and surface type (e.g., more pavement leads to less
infiltration and more runoff --- leading to less groundwater recharge).
Formative Assessments
1. Use the School Map assessment to assess students’ levels of achievement for reading
two-dimensional representations of three-dimensional space.
2. Use the Wash Trash Assessment to assess student level of achievement for tracing
water.
Target Explanation and Reasoning
What is a watershed? Where does the water flow in my watershed?
A watershed is all of the land area that drains water to one place. Gravity pulls water
downwards and the topography of the land controls the pathway of the water across the land
surface. As a result, within a watershed, water flows in tributaries from high elevations into
larger streams in lower elevations. Areas of higher elevation separate adjacent watersheds.
Watershed can be nested within larger watershed.
When does water run off? (or, why are there flash floods in urban and desert areas?)
Surface type constrains how much water runs off in a watershed. On permeable surfaces, some
water will infiltrate into the ground (pulled down by gravity); on impermeable surfaces, most
water will run off. On surfaces that are vegetated, water runs slower, allowing more water to
infiltrate.
 On forests, grasslands, or wetlands, vegetation cover slows surface water flow, allowing
more water to infiltrate into the ground.
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Reasoning Tools for Understanding Water Systems


On agricultural land, when fields are fallow, water runs off more quickly and not as
much water will infiltrate into the ground. Increases in rates of runoff also increase
erosion from agricultural lands.
On residential or urban land, there is usually more impermeable surface, resulting in
more runoff and less infiltration.
In urban areas, there are many surfaces, such as roads, sidewalk, parking lots, or rooftops, that
are impermeable. Water runs off quickly and does not infiltrate. In desert areas and also
agricultural areas where there is bare ground, water may infiltrate at a slower rate than the
rate of precipitation and the ground will become saturated quickly in a rain event. The rain then
runs off. In both of these situations, it does not take much rain for a large runoff event. In areas
with lots of vegetation, the vegetation slows the rate of runoff, allowing more water to
infiltrate. As a result, in vegetated areas, runoff from the same size precipitation event may not
be as large as in areas with impermeable surfaces or bare ground.
How does human activity impact surface water runoff in watersheds?
In areas where people decrease the area of land covered by forests, grasslands, and wetlands,
and increase the area covered by agriculture and urban areas, the volume of runoff will
increase. The reason is because in areas converted to residential areas, the permeability of the
land is decreased and less water is able to infiltrate, meaning more water runs off. In areas
converted to agricultural land, the water runs off faster than when it was forest, grassland, or
wetland, meaning there is less opportunity for the water to infiltrate into the ground. As a
result, there is an increase in runoff.
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Reasoning Tools for Understanding Water Systems
Watershed Models
Summary of Activity
Students build a three-dimensional model of the local watershed and trace water through the
watershed.
Materials:
 Several tarps
 Various size plastic plant pots to create topography under tarp
 3 watering cans and/or spray bottles
 Student handouts for each student
 Blue yarn to mark rivers and lakes
 Green yarn to mark watershed boundaries
 Laminated cards (see pages 3 & 4)
 Towels for wiping up spills
 A compass for finding cardinal directions
 A blank Pathways Tool for each student
Time:
What is a Watershed? ~15 minutes
Getting the Lay of the Land ~25 minutes
Building the Watershed Model ~25 minutes
Check your Ideas about Watersheds ~25 minutes
Question: Establish a question and elicit student ideas.
What is a Watershed?
1. Ask students to complete the “What is a Watershed?” sheet. This activity will give you an
opportunity to elicit student ideas.
2. You may want to administer this the day before you complete the other activities so that
you’ll have an opportunity to review students’ ideas about watersheds.
3. Optional: Have students share out their ideas about what a watershed is. You may choose
to use a document projector so that students can share their drawings.
Explain: Introduce scientific ideas and Apply: Apply scientific ideas (model, coach, fade)
Getting the Lay of the Land
1.
Pass out a map and a “Getting the Lay of the Land” handout to
Practices
each student.
 Using Models
2.
Students should work in pairs on the “Getting the Lay of the Land”
questions.
3.
If possible, project the map on a SmartBoard and, during whole class discussion, have
individual students come to the front and complete the handout questions on the map.
Allow the class to agree/disagree and come to consensus on how the questions should be
answered.
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Reasoning Tools for Understanding Water Systems
4.
For Tucson students who are not familiar with water in the Rillito or Santa Cruz Rivers,
these video links show footage of water flowing in these waterways.
Santa Cruz River in 2005 and 1993 http://gallery.usgs.gov/videos/208#.T_IhZJFSTGg
Santa Cruz River in 2011 - http://www.kgun9.com/multimedia/videos/?bctid=1162052053001
Rillito Wash- http://www.tucsonwebcam.com/
Building the Watershed Model
1. Use the directions below to facilitate the students in creating the Bitterroot Watershed
model. Make sure all students get to help with at least one task. As students complete the
tasks, engage the rest of the group in a discussion concerning whether they agree with the
way the model is being built, or if they have any suggestions for changes.
2. (~3 students) Decide (or use the compass) to determine which direction will be North. Show
students how big the tarp is so they get a sense of how big their watershed model should
be. Tell students to use the plastic flower pots to start building the topography (shape for
the land) for model. When the model is done, it should represent the watershed. The
biggest pot should be used for the highest elevation on the map. The lowest elevation on
the map can be at ground level. The arrangement doesn’t need to be perfect, but it should
give an overview of the shape of the land. When the three students are done, check with
the rest of the group that they are happy with the arrangement. If not, have
the students make changes as needed.
Practices
Using
Models
3.
(~3 students) Now place the tarp on top of the pots. Arrange the tarp
so that it provides a pretty good model of the watershed. Again, the rest of
the group can help guide the students who are working with the model. The
students should adjust the model as needed. This group should place the
following cards on the model in the appropriate places:
a. The North Arrow to show direction
b. Major landforms
i. MT: Sapphire Mountains, Bitterroot Mountains, Lost Trail Pass
ii. AZ: Mount Lemmon (Santa Catalina Mountains), Tucson Mountains, Tucson
4. (~3 students) Students should use blue yarn to mark where they think rivers (or washes) will
be on the model. They don’t need to show every creek, but should show some main
waterways such as the Bitterroot River for MT or the Rillito and Santa Cruz Rivers for AZ and
a few tributaries. Don’t just use the map --- use the model to show where water will be
likely to flow. Next place arrow cards on the model to show which direction water will flow
in the waterways. The students should also place cards marking the major rivers or washes
on the map.
5. (~3 students) These students get to test out the model with water. Use the watering cans to
slowly rain water onto the model. Rain should fall on different places in the model. The
whole group should carefully observe where the water goes on the model. Does the water
follow the expected directions indicated by the arrows? Is the water moving into and
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Reasoning Tools for Understanding Water Systems
through the rivers and creeks indicated with blue yarn? Does water drain to the expected
place on the model?
6. (~3 students) These students’ job is to mark the boundary of the watershed on the model
(Bitterroot for MT; Rillito for AZ). The definition of a watershed is an area of land where all
the water that falls on that area of land drains to the same place. The place where the
water drains to is usually a body of water such as a river, lake or ocean. The Bitterroot River
Watershed is the area of land in which all the rain that falls drains to the Bitterroot River.
The Rillto Watershed is the area of land in which all the rain that falls drains into the Rillito
Wash. Now that you know the definition, outline the boundary of the Bitterroot River or
Rillito Wash Watershed on the model with green yarn.
Reflect: Reflect on changes in ideas
Check Your Ideas about Watersheds
1. Pass out a “Check your Ideas about Watersheds” handout to each student.
2. Students should work in pairs on (or lead the whole group in discussion about) the “Check
Your Ideas about Watersheds” questions.
3. Have students complete a Pathways Tool addressing question 6 from the “Check Your
Ideas” questions. In the middle box, MT students should fill in “Bitterroot River near Darby”
and AZ students should fill in “Pantano Wash.” You may choose to give students a more
detailed watershed map of the area for completing this activity. Students should work in
pairs to trace back where the water could have been before it was in the river near Darby or
in the Pantano Wash. Students should trace forward where water with oil in it might go
after the spill. Some students may indicate that for some movements, water and oil will
separate (e.g., some water will go to atmosphere but no oil will. This is fine.)
4. If possible, project the handout on a SmartBoard or with an LCD projector and, during
whole class discussion, ask students to share their ideas and responses. Allow the class to
agree/disagree and come to consensus on how the questions should be answered.
5. Ask students to share their completed Pathways Tool (Use a document camera if available.
If not, students can write their pathways on the board.) Ask other students in the class if
they agree or disagree that the identified pathways show places where the water could
have come from and where the oil and water could go to after the spill. If students disagree,
ask them to explain why and to explain where they think the materials could have come
from and where they could go to.
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Reasoning Tools for Understanding Water Systems
Cards to Laminate: Bitterroot Watershed Version
Copy, cut out, and laminate the cards below.
HAMILTON
SULA
TRAPPER PEAK
KENT PEAK
DARBY
LOLO
BIG CREEK
LOST TRAIL PASS
STEVENSVILLE
LOLO CREEK
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Reasoning Tools for Understanding Water Systems
25
Reasoning Tools for Understanding Water Systems
BITTERROOT MOUNTAINS
BITTERROOT RIVER
SAPPHIRE MOUNTAINS
N
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Reasoning Tools for Understanding Water Systems
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Reasoning Tools for Understanding Water Systems
Cards to Laminate: Rillito Watershed Version
Copy, cut out, and laminate the cards below.
Tucson
Mount Lemmon
Mountains
Tucson
Rillito Wash
Santa Cruz River Cañada del Oro
Sabino Canyon
Pantano Wash
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Reasoning Tools for Understanding Water Systems
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Reasoning Tools for Understanding Water Systems
Check Your Ideas about Watersheds Example Answer Key
1. What force causes water to move in our watershed model?
Gravity.
2. What impacts which way water will flow over the surface of the ground in a watershed?
Topography (shape of the land). Liquid water moves toward lower elevation, whichever
direction that may be based on the shape of the land.
3. Does a watershed boundary always have to be mountain ridge? YES NO
Explain why
or why not.
No. In places where the land is relatively flat, such as areas of the Midwest and Great Plains
in the United States, watershed boundaries may represent small rises in elevation that are
not even perceptible to the eye.
4. Does the model you have built show just one watershed, or does it show more than one? If
it shows more than one, explain where the other watersheds in the model are.
Many watersheds are shown in the model. Each of the creeks shown has its own watershed
nested within the Bitterroot River Watershed. In addition, all of the land represented
outside of the Bitterroot River Watershed boundary shown on the model with the green
yarn represents land in other watersheds outside of the Bitterroot Watershed.
5. Does all of the water that falls as rain in the Bitterroot River/ Rillito Watershed flow over
the ground? YES NO If no, where else can the water that falls as rain go?
No. Water that falls as rain in the watershed could go to several other places besides
flowing over the ground. For example:
A. If the ground where the rain falls is permeable, some of the water will infiltrate into the
ground and become groundwater. Groundwater generally flows underground in the
same direction as water flowing above ground. Groundwater can leave the ground
either by discharging back into surface water (e.g., back into a river or into a lake), or it
could be pumped out of the ground through a well.
B. Some water could also evaporate from creeks and rivers and return to the atmosphere
as water vapor.
C. Some water could also be used by plants (absorbed through their roots) and animals.
6. If a tanker truck carrying gasoline had a rollover accident and spilled gasoline near Darby,
where could the gasoline end up? Could any gasoline end up in Skalkaho Creek? How do
you know?
If the gasoline spilled near a river crossing, it might get directly into the Bitterroot River and
flow north toward Missoula. Even if it didn’t spill right next to the river, some gasoline might
infiltrate through the ground and end up in the groundwater and possibly in the river.
Gasoline could not end up in Skalkaho Creek because Skalkaho Creek is at a higher elevation
and liquid water does not flow uphill.
6. If a tanker truck carrying gasoline had a rollover accident and spilled gasoline in the Pantano
Wash, where could the gasoline end up? Could any gasoline end up in Cañada del Oro?
If the gasoline spilled in the Pantano Wash when there was water flowing in the wash, it
could flow into the Rillito Wash and then into the Santa Cruz River. If there was no water in
the wash, the gasoline would likely just infiltrate into the soil and possibly into the
groundwater. No gasoline would end up in Cañada del Oro because Cañada del Oro is
higher in elevation and liquid water does not flow uphill.
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Reasoning Tools for Understanding Water Systems
What is a Watershed?
Draw and label what you think a watershed is. Explain the drawing in your own words,
describing what is happening in the watershed and why.
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Reasoning Tools for Understanding Water Systems
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Reasoning Tools for Understanding Water Systems
Getting the Lay of the Land (Bitterroot Watershed)
1. Working with a partner, take a look at the map provided. Mark the directions (N,E,S,W) on
the compass rose.
2. Find the place with the highest elevation on the map. Circle it and write HIGH by the circle.
Next find and circle the place with the lowest elevation on the map. Circle it and write LOW
by the circle.
3. What prominent landforms are located to the west of the Bitterroot River?
4. What prominent landforms are located to the east of the Bitterroot River?
5. Compare the southernmost place that is marked on the map with the northernmost place
that is marked on the map. Which one is at a higher elevation?
6. In which general directions do the creeks to the west of the Bitterroot River flow? Draw
arrows on the creeks to the west of the Bitterroot River to show which direction they flow.
7. In which general directions do the creeks to the east of the Bitterroot River flow? Draw
arrows on the creeks to the east of the Bitterroot River to show which direction they flow.
8. In which direction does the Bitterroot River flow? Draw arrows along the Bitterroot River to
show the direction of flow.
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Reasoning Tools for Understanding Water Systems
Check Your Ideas about Watersheds (Bitterroot Watershed)
Answer the following questions with your team to check your ideas about how watersheds
work.
1. What force causes water to move in our watershed model?
2. What impacts which way water will flow over the surface of the ground in a watershed?
3. Does a watershed boundary always have to be mountain ridge? YES NO
or why not.
Explain why
4. Does the model you have built show just one watershed, or does it show more than one? If
it shows more than one, explain where the other watersheds in the model are.
5. Does all of the water that falls as rain in the Bitterroot River Watershed flow over the
ground? YES NO
If no, where else can the water that falls as rain go?
6. If a tanker truck carrying gasoline had a rollover accident and spilled gasoline near Darby,
where could the gasoline end up? Could any gasoline end up in Skalkaho Creek? YES NO
How do you know?
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Reasoning Tools for Understanding Water Systems
Rillito Watershed
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Reasoning Tools for Understanding Water Systems
Getting the Lay of the Land: Rillito Watershed
1. Working with a partner, take a look at the map provided. Mark the directions (N,E,S,W) on
the compass rose.
2. Find the place with the highest elevation on the map. Circle it and write HIGH by the circle.
Next find and circle the place with the lowest elevation on the map. Circle it and write LOW
by the circle.
3. What prominent landforms are located to the north of the Rillito Wash?
4. Compare the southernmost place that is marked on the map with the northernmost place
that is marked on the map. Which one is at a higher elevation?
5. In which general directions do the creeks flow off Mount Lemmon into Rillito Wash? Draw
arrows on these creeks to show which direction they flow.
6. Into which river do creeks and washes flowing off the Tucson Mountains flow? In which
general directions do the creeks from the Tucson Mountains flow? Draw arrows on these
creeks to show which direction they flow.
7. In which direction does the Rillito Wash flow (when it rains)? Which direction does the
Santa Cruz River flow (when it rains?) Draw arrows along these rivers to show the direction
of water flow when it rains.
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Reasoning Tools for Understanding Water Systems
Check Your Ideas about Watersheds (Rillito Watershed)
Answer the following questions with your team to check your ideas about how watersheds
work.
1. What force causes water to move in our watershed model?
2. What impacts which way water will flow over the surface of the ground in a watershed?
3. Does a watershed boundary always have to be mountain ridge? YES NO
or why not.
Explain why
4. Does the model you have built show just one watershed, or does it show more than one? If
it shows more than one, explain where the other watersheds in the model are.
5. Does all of the water that falls as rain in the Rillito Wash flow over the ground? YES NO
If no, where else can the water that falls as rain go?
6. If a tanker truck carrying gasoline had a rollover accident and spilled gasoline in the Pantano
Wash, where could the gasoline end up? Could any gasoline end up in Cañada del Oro? YES
NO
How do you know?
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Reasoning Tools for Understanding Water Systems
Tracing a Watershed
Adapted from a lesson developed by Colleen Windell
Activity Summary
Students explore a map showing their own watershed. They identify tributaries and watershed
boundaries for their watershed. Students also use the map to identify smaller watersheds that
are nested within their own watershed, and/or larger watersheds that their own watershed is
nested within. Students will deepen their understanding of the concept of a watershed, of how
watersheds are interconnected, and of how the place where they live is part of a specific
watershed. Students will also use Pathways and Drivers and Constraints Tools to trace water
and think about what moves water through different pathways into, through and out of
different places in their watershed.
Time: Two to three 45 minute class periods
Materials:
 Enough laminated topographic maps of students’ watershed (e.g., Lolo Creek, Rock Creek,
etc.) for students to work with maps in groups of 3-4. If students live in a large watershed
(e.g., Clark Fork River Watershed) you may choose to have different groups work on subbasins within the watershed.
 Maps showing larger watershed in which students live (e.g., Columbia River Basin, Colorado
River Basin, etc.)
 Vis-à-Vis markers
 Large tracing paper
 Blank Pathways Tools for students to complete in groups
 Blank Drivers and Constraints Tools for students to complete in groups
 Exploring My Watershed handouts
Procedure:
Question: Establish the driving question & elicit student ideas
1.
Begin by asking students, “Where does all the water come from that flows
Practices
in [name of river or creek near school]? And, “If an oil tanker over turned and
Asking
spilled oil into [river or creek near school], how far away would the effects be
questions
felt?” Ask students to write their ideas down in their science journals. After a few
minutes, have students share their ideas with the class.
Explore & Investigate: Explore phenomena for patterns
2. Assign students to groups of 3-4. Each student should get an “Exploring My Watershed”
worksheet that they can follow to complete the rest of the lesson activities (see below).
Give each group a laminated map of their local watershed and a Vis-à-Vis marker. Have
students find the waterway (e.g., creek, rivers, wash) nearest to their school. Next have
students find the largest river in their watershed that is shown on the map. Have
Practices
the students trace with the Vis-à-Vis marker from the largest river upstream finding
Using
and marking all of the other rivers and creeks that flow into the main river. NOTE: If
Models
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Reasoning Tools for Understanding Water Systems
students live within a large watershed with many rivers and streams above it, you may
decide to have students trace just part of their upstream watershed (e.g., just the
Rattlesnake Creek Watershed).
3. Next, give each group a large piece of tracing paper and have them trace the rivers and
streams they have marked on the tracing paper. Ask the students to then draw in a border
line – a line that connects the ends (sources) of all of the rivers and streams. Students
should label on their tracing paper the names of major streams and rivers, the watershed
boundary, and the source of several streams. Students should also mark with arrows the
direction of water flow on the streams and rivers on their tracing paper watershed map. If
students are using topographic maps and are familiar with how they work, students should
mark the places with the highest and lowest elevations in their watershed, indicating the
elevation of both places.
4. Hand out a laminated map of the overarching watershed that your school is part of (i.e.,
often a watershed that empties into an ocean). Have students locate their own watershed
within the largest watershed. Students should observe how their own smaller watershed is
connected to the larger watershed. Have students use the Vis-à-Vis pen to mark the path
from their own watershed through the larger watershed to the ocean or other
Practices
large body of water shown (e.g., Columbia River).
Using Models
5.
Students in their groups next work on their Pathways Tools. Mark an X in a
different place on each groups’ map and have them write the name of the place
with the X into the center block on their tool (e.g., confluence of Bitterroot River and Clark
Fork River). Groups should complete their pathways tool first indicating surface water
places on their map where the water could have come from and where it could go to from
the X marked on their map. Next, students can fill in more pathways on their tool by
thinking about other places water could come from and go to besides the surface water
system (e.g., rain from atmosphere, infiltration into ground, use by plants and animals,
etc.). Support students in thinking about multiple pathways that may increase in number as
students get further in either direction from the place marked on their map. After students
complete their Pathways Tools, the groups can share, compare and discuss what they
wrote. Why are the Tools from the different groups not all the same? Do the students agree
that the paths identified by the other groups are all reasonable? How do they know?
Explain: Students develop explanations
6. Have students work in their groups and with the Pathways Tool and their watershed maps
to consider the implications of the interconnectedness of watersheds (e.g., how what
people do upstream in a watershed can affect people and places downstream in a
watershed.) Ask students probing questions such as:
a. Where does water in Milltown come from?
b. Can water in Milltown end up in Lolo via a surface pathway? Why or why not?
c. Can water in Missoula end up in Alberton via a surface pathway? Why or why not?
d. Can water in Tucson end up in Mexico via a surface pathway? Why or why not?
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Reasoning Tools for Understanding Water Systems
e. When we change the water quality in the Clark Fork River in Missoula, who is
impacted?
f. Who and/or what impacts the quality of water in the Clark Fork River in Missoula?
g. What kinds of materials and substances do you think will move down a watershed in
surface water? What kinds of materials or substances won’t?
Similar questions can be asked for the Rillito Wash and Santa Cruz River
7. If you haven’t done so already, take time to introduce to students how the Drivers and
Constraints Tool works before you ask them to work on the tool in their small groups.
Project the Drivers and Constraints Tool and discuss what the aspects of the tool mean
and how to use.
a. Drivers are forces that move water. Use example of water on a hill that starts on the
side of the hill. If it goes over the ground, which direction will it move? (Down).
What’s the force that moves it? (Gravity). The name of this is runoff.
b. Constraints are things that limit how or how much something happens. So your
parents may limit how much TV you can watch. That’s a constraint. And the law
limits you from driving until you’re sixteen. That’s a constraint. With water,
constraining factors limit how fast or slow, how much, or in which direction water
moves. Use slope as an example. Draw a steep slope and a shallow slope on the
board and ask students how these two slopes will affect how fast or slow water
moves. Then draw two slopes slanting in different directions and ask students how
these two slopes will direct which direction water moves.
c. Next go through an example of a row of the Drivers and Constraints Tool as a class -- for example you might use the river to atmosphere example described below in
procedure 9. Try to co-construct the responses with students by asking for their
ideas rather than just telling students what should go in the boxes.
8. Next ask students to complete a Drivers and Constraints Tool based on their Pathways Tool.
The students should choose three different linked pathways from their Pathways Tools and
fill these links into the three rows on their Drivers and Constraints Tool. For example, one
row of their Drivers and Constraints tool might indicate that water starts in the Santa Cruz
River and moves to being water vapor in the atmosphere. Students can complete the other
cells of the Drivers and Constraints row by thinking about what the process is named
(evaporation), what drives the process (heat energy), and what constrains the process (e.g.,
humidity, temperature, surface area of river).
9. Take time for groups to share their Drivers and Constraints Tools (with a document
projector if available; otherwise by writing on board. The class can evaluate the different
responses and help refine each other’s ideas about how and why water moves through the
different pathways that students identified.
10. Ask each group to turn in their labeled tracing paper watersheds, their completed Pathways
and Drivers & Constraints Tools, and their answers to the challenge questions you posed.
40
Reasoning Tools for Understanding Water Systems
Names:
Exploring My Watershed
Directions:
1. Locate [name of river or stream near school] on the map.
2. Mark the length of [river or stream near school] with the Vis-à-Vis pen.
3. Find the largest river on the map that is part of the same watershed as [river or stream near
school].
4. Starting at the most downstream spot on the largest river on the map, use the Vis-à-Vis
marker to mark the rivers and streams that flow into the large river you found.
5. Get a piece of tracing paper from the teacher and trace all the rivers and streams you
highlighted onto the tracing paper.
6. Draw a line that connects the beginning of all the streams that you have traced. This should
form an odd shaped ring around the largest river in your watershed on your map.
7. On your tracing paper, label the following:
a. Names of major streams and rivers
b. Watershed boundary
c. The source of several streams
d. The direction of water flow in streams and rivers (using arrows)
e. The place that you think has the highest elevation in your watershed
f. The place that you think has the lowest elevation in your watershed
41
Reasoning Tools for Understanding Water Systems
Pathways Tools:
Simpler One Pathway Example:
More Complex Multiple Pathways Example:
42
Reasoning Tools for Understanding Water Systems
Pathways Tool
With your group, complete the Pathways Tool below, thinking about where water in your
community comes from and where it goes to.
Pathways Tool Example
43
Reasoning Tools for Understanding Water Systems
Drivers and Constraints Tools:
Example:
44
Reasoning Tools for Understanding Water Systems
Exploring Runoff & Surface Type
Summary of Activity
Students compare three surface types to explore how surface type affects runoff infiltration.
Time: 45 minutes
Materials
For each group:
1. Paint tray or paint tray liner. If you use liners, you will need books or other inclined
surface on which to place the paint tray liner. Punch or drill a drain hole in the deepest
end.
2. Plug for the hole in the paint tray.
3. Bucket or large container to collect water
4. Rain cup – plastic cup with small holes in the bottom
5. Graduated cylinder
6. Sand
7. Soil
8. Sod (you can model with a piece of old carpeting)
9. Asphalt shingle – if available. If not, just use the empty paint tray.
10. Timer
Activity
Driving Question: Why do urban and desert areas have to worry about flash floods?
Question:
1. Establish the driving question
a.
Consider a rainstorm that drops 0.5 inches of rain. Will this
Practices
cause a flood? It might in a desert or in a poorly designed urban area.
 Asking Questions
b.
Show students a video of a flash flood
http://www.tucsonwebcam.com/
c.
Ask students why there might be flash floods in the desert.
2. Elicit student ideas.
a. Students can write their ideas in their science
notebooks, then share ideas with a partner or the whole class.
b. Push students to explain why.
Explore & Investigate
3. Explore phenomena for patterns
a. Begin with the empty paint tray. Set it up so that it sits on an incline,
with the deepest end over the edge of the table so that water drains
out of the drain hole and into a bucket or graduated cylinder. If you
are using an asphalt shingle to represent a road surface, place the
shingle in the bottom of the tray.
45
Reasoning Tools for Understanding Water Systems





b. Pour 100 ml of water into the rain cup. Let the rain fall onto the paint
tray or shingle. Use a time to measure 15 seconds. Then plug the
Practices
drain hole (finger will do, or a small piece of clay).
Using Models
c.
Measure the volume of water in the bucket. Record the findings.
Analyzing and
d. Repeat 2 more times and average the results.
Interpreting Data
e. Fill the tray with a small amount of sand. This setup represents a
desert wash. You may also cover the sand with soil to represents bare
soil, such as in an agricultural setting.
f. Pour 100 ml of water into the rain cup. Let the rain fall onto the soil.
Use a time to measure 15 seconds. Then plug the drain hole (finger
will do, or a small piece of clay).
g. Measure the volume of water in the bucket. Record the findings.
h. Repeat 2 more times and average the results.
i. Cover the soil with the sod or carpet square to represent a vegetated
surface.
j. Pour 100 ml of water into the rain cup. Let the rain fall onto the soil. Use a time
to measure 15 seconds. Then plug the drain hole (finger will do, or a small piece
of clay).
k. Measure the volume of water in the bucket. Record the findings.
l. Repeat 2 more times and average the results.
4. Identify patterns
a. Students may graph results. Which type of surface had the most runoff?
Explain
5. Students explain patterns
a. Use the Drivers and Constraints Tool to have students work in groups to develop
their explanation for the pattern they noticed.
6. Students compare ideas
a.
Have students present their Drivers and Constraints Tools to the
Practices
class. Compare tools from different groups.
Constructing
Explanations
b.
Introduce scientific ideas.
Developing
c.
Help students notice, if they have not already, that the vegetated
Arguments from
surface slowed down the water so that it was able to infiltrate
Evidence
into the soil below. On unvegetated surfaces, the water ran off
Evaluating and
too fast. On the impermeable surface, no water was able to
Communicating
infiltrate and it all ran off.
7. Students answer driving question
a.
Using their Drivers and Constraints Tool, have students explain
Practices
why desert or urban areas have to worry about flash floods.
 Constructing
Students should develop their arguments and defend arguments
Explanations
 Developing
to other groups.
Arguments from
b.
Have students write their explanation in their science notebooks.
Evidence
 Evaluating and
Communicating
46
Reasoning Tools for Understanding Water Systems
Where does the
water start?
Rain on the asphalt
Where does the water go?
What are the drivers?
What are the constraints?
Runs down the slope
Gravity pulls water
down
The water cannot infiltrate into the
asphalt because there is no openings
for the water to go into, so all the
water runoff.
Gravity pulls water
down
The soil and sand has pore spaces. As
the water land on the surface, some
water sinks into the pore spaces.
When the pore spaces are full, the
water runs off.
Gravity pulls water
down
The grass slows down how fast the
water runs across the surface. As a
result, there is more time for the
water to infiltrate into the soil below
and less water runs off.
Runoff
Rain on the bare soil
Most runs down the
slope. Some sinks in
to the soil.
Runoff & infiltration
Rain on the grass
Slowly runs down the
hill or sinks into the
soil..
Runoff & infiltration
47
Reasoning Tools for Understanding Water Systems
Color Me a Watershed
Summary of Activity
Students compare three maps to see how development can affect a watershed.
See Project Wet, pages 223-231.
Prior Activities
Prior to engaging in Color Me a Watershed activity, students should have some experiences
with watersheds. Suggested activities include:
 Watershed Models: 3-dimensional watershed models (e.g., tarp activity, crumpled
paper watersheds, large scale watershed models) (Activity 1 in this sequence)
 Tracing Watersheds: Tracing water through watersheds using 2-dimensional map
representations (Activity 2 in this sequence)
 Exploring Runoff & Infiltration (Activity 3 in this sequence).





Tools for Reasoning
Tracing Pathways–
1. Use the maps and the Pathways Tool to scaffold interpreting two-dimensional
representation of three-dimensional space and tracing water in the stream. The idea is to
help students interpret which direction runoff flows.
a. On Map A, assign each student, pair of students, or group of students to a pixel (it
might help to add letters and numbers along the axes to facilitate identification of
pixels.) You may assign the same pixel to more than one
student, pair, or group. Students should indicate their pixel
Practices
location on the Pathways Tool.
Using Models
b.
Have students trace backwards where they think the water in
Analyzing and
that pixel might have come from and where it will go to.
Interpreting Data
Encourage student to think about multiple possibilities for
pathways.
c.
Have students consider where the water in that location will
go next. Encourage students to think about surface, soil, and
atmospheric locations.
d. It may help to have students draw the pathways on the map
as well.
e. Note: To begin, choose pixels in the stream. Use land pixels
Practices
after students do the Drivers and Constraints Tool below. The
Constructing
Explanations
idea is to help students interpret which direction runoff flows.
Developing
f.
Allow students with the same pixel to compare their pathways
Arguments from
tools. Support students in explaining their thinking about the
Evidence
pathways they traced.
Evaluating &
g. On the back of the Pathways Tool or in their science
Communicating
notebooks, have students write down their explanation for
the Pathways that they traced.
48
Reasoning Tools for Understanding Water Systems
Before
Stream
Runoff
Runoff or
infiltration
from
Wetlands
(J13, L13, L14,
E14)
Rain
After
Before
After
Stream
runoff (I14,
J14, K14, H14)
Rain
Before
Stream runoff
J15, I 15
Where is the water?
Residential
Agricultural
runoff K15
Pixel J16
Stream
After
Stream J18,
K18
Stream J17
Evaporation
Stream J19,
K19, L19
Evaporation
Condensation
maybe
precipitation
Rain
2. Drivers and Constraints Tool – Use the Drivers and Constraints Tool to support students in
thinking about whether water will infiltrate or runoff from the land the surface.
a. Assign students, pairs, or groups to a pixel. Put this pixel where the water starts.
b. Have students complete the Drivers and Constraints boxes for the water in that
pixel. Hints:
Drivers – What moves the water (Gravity pulls water down). It will either
runoff or infiltrate depending on.
Practices
 Using Models
 Analyzing and
Interpreting
Data
Practices
 Constructing
Explanations
 Developing
Arguments from
Evidence
 Evaluating &
Communicating
Constraints –
Topography – direction to lower land
Permeability & vegetation
Forest, grassland, or wetland – most will probably infiltrate.
Water has time to infiltrate in.
Agriculture – some infiltration, some runoff because bare
soil can become saturated quickly.
Residential – mostly runoff because permeability is
decreased.
c. Now have student complete the boxes for where water moves
and the process (runoff or infiltration).
d. Allow students with the same pixel to compare their Drivers and
Constraints tools. Encourage students to discuss why their Tools
are similar or different. Support students in coming to consensus.
49
Reasoning Tools for Understanding Water Systems
e.
On the back of the tool or in their science notebooks, have
students write an explanation for where water in their assigned
pixel will go.
Where does the
water start?
K7 Grasslands
Map A 100 years
ago
What are the drivers?
Gravity pulls water
down
What are the constraints?
Topography – water will flow to lower
elevation. It can’t go north because that is a
higher elevation.
Permeability – Water moves slower across
grasslands. Grasslands are also more
permeable, so most of the water will likely
infiltrate.
Where does the water go?
To the wetlands in
K8 through the
ground
Process - Infiltration
Exploring the Relationship between Landuse and Runoff Volume –
2. Use the Drivers and Constraints tool to support student in considering why the runoff
increased from the time represented in Map A (100 years ago) to the time represented in
Map C (present).
a.
Have students complete a Drivers and Constraints tool for the
Practices
same pixel on each map.
 Using Models
b.
Compare the results. Have students provide initial
 Analyzing and
Interpreting Data
explanations for what is happening to the runoff. They should
notice that there is more runoff as the land is covered by more
agricultural and residential usage.
c.
Do Option 2. You may also decide to do Option 3. Make
Practices
appropriate accommodations for time and student
 Using
computation skills. For example:
Mathematics &
i.
Give students the land areas and water runoff
Computational
volumes in the table on page 225 and 226.
Thinking
ii.
If you would like students to do the calculations, you
could have different groups complete the
calculations for different land coverage types (e.g.,
Practices
group A calculates areas for forests, group B
 Constructing
calculates areas for grasslands, etc.)
Explanations
d. In pairs or groups, students can use their completed Drivers
 Developing
Arguments from
and Constraints tools and the tables to develop an explanation
Evidence
for why the runoff volume increases as the land use changes.
 Evaluating &
Students can then write this explanation in their notebooks or
Communicating
on the back of the tool.
e. Engage students in presenting their explanations to the rest of
the class. Groups can evaluate each other’s arguments.
50
Reasoning Tools for Understanding Water Systems
Where does the
water start?
K7 Grasslands
Map A 100 years
ago
K7 Residential
Map B 50 years ago
K7 Residential
Map C Present
What are the drivers?
Gravity pulls water
down
Gravity pulls water
down
Gravity pulls water
down
What are the constraints?
Topography – water will flow to lower
elevation. It can’t go north because that is a
higher elevation.
Permeability – Water moves slower across
grasslands. Grasslands are also more
permeable, so most of the water will likely
infiltrate.
Topography – water will flow to lower
elevation. It can’t go north because that is a
higher elevation.
Permeability – Residential areas have more
impermeable surfaces, so water will runoff
rather than infiltrate.
Topography – water will flow to lower
elevation. It can’t go north because that is a
higher elevation.
Permeability – Residential areas have more
impermeable surfaces, so water will runoff
rather than infiltrate.
Where does the water go?
To the wetlands in
K8 through the
ground
Process - Infiltration
To the stream
flowing south
Process - Runoff
To the stream
flowing south
Process - Runoff
51
Reasoning Tools for Understanding Water Systems
52