2.1 Where is water found?

Lesson Overview

Guiding question:

Where is water found?

3 Hours

Purpose:

Students will explore the ways water is stored on Earth and how it is moved through Earth through the Water Cycle.

Overview:

The students will learn about surface water and groundwater and their role in the water cycle, the development of cities, and the impacts of human intervention. Using examples of the Hoover Dam and High Plains aquifer, the students will work closely with real-world data to draw their own conclusions about the future of water.

Design Principles:

Public Data
Modeling

Background Knowledge:

A rudimentary understanding that water is moved through Earth through a series of processes (ex. Ocean→ clouds→ rain→ ocean).

Common Misconceptions:

Water disappears: Some students may think that water simply disappears when it evaporates or falls as precipitation. They may not realize that water is continually cycling through the different stages of the water cycle.
Water comes only from rain: Students may believe that rain is the sole source of water, overlooking other forms of precipitation such as snow, sleet, or hail. They may not fully understand that water can be present in different states and can transition between them.
Water only exists on the Earth’s surface: Some students may not realize that water also exists in the atmosphere as water vapor. They may think that water is only found in oceans, lakes, and rivers.
Water always evaporates from the same place it condenses: Students may have difficulty grasping that water vapor can travel long distances before condensing to form clouds and eventually precipitating as rain or snow. They may think that the water evaporated from the same area it falls as precipitation.
The water cycle is a one-time process: Some students may not recognize that the water cycle is an ongoing, continuous process. They may believe that once water falls as precipitation, it never returns to the atmosphere.

Safety:

Unit Connections:

Teacher

Teacher Slides: 2.1 Where is water found?
Lesson Set 2 Answer Keys
Example water cycle models
1-gallon jug full of water, colored with blue food dye for easier viewing
1 glass bowl or clear container, big enough to hold 1 gallon
1 tablespoon

Student

2.1 The Hoover Dam & Lake Mead
2.1 High Plains Aquifer & Agriculture
A way to keep up with their different versions of the water cycle models

Optional

Teacher Slides: Reading Graphs
Whiteboard & markers (1 per group)
The Hoover Dam & Lake Mead Audio File
High Plains Aquifer & Agriculture Audio File

Instructional Sequence

Materials: Teacher Slides: 2.1 Where is water found?

Class Discussion (slide 1-3)

Review the previous lesson set’s objectives by having students discuss with a partner or in their groups the questions on slide 1. Students should make connections to lesson 1.1 about different people having different relationships with water.

Have students share thoughts as time allows

The teacher may need to review what “water stress” means before starting. Water stress is a situation in which the water resources in a region or country are insufficient for its needs.

Class Discussion and

Peer-to-peer discussion

Teacher Simulation: What if all of Earth’s water was only 1 gallon? (Slides 5-10)

Hold up the gallon of water. If you want, emphasize how heavy a gallon of water is. You can have different students come up to the front to feel it as well.

State to the class:

This is all the water of planet Earth.

This is the water that is seen from space in the oceans that make people call this the blue planet.

This is the glaciers that make up the northern and southern poles and rest atop mountain ranges. This is the rivers, the lakes, the tiny ditches along a rural road filled with water. This is the precipitation from every single rainy day for which you have ever been alive. This is the water in your afterschool sports drink, the water in your faucet used to brush your teeth, the water used by farmers to irrigate their crops, the water required to complete nearly every single task on this planet. Pour the gallon of water into the glass or clear container.

Allow students to predict how much water is available for our use

Measure out 8 tablespoons from the clear container, pour the back into the gallon jug, counting aloud as you go. Hold up the still nearly empty jug and state to the class: this is all the water NOT in the ocean, which is about 3% of all the water on planet Earth. All the rest of this water is what makes our Earth blue, the salty waters of the oceans that separate our continents and communities.

Measure out 1 1⁄2 tablespoons out of the 8 tablespoons from the gallon jug and pour back into the clear container and state to the class:

Unfortunately, about .5% of the Earth’s water is still salt water even though it’s NOT in the ocean, so it’s also not usable by humans. This includes landlocked bodies of water like the Great Salt Lake and the Dead Sea, which can have an even higher salt concentration than the ocean.

We also have something called brackish water, which is a mix of salt and freshwater.

Hold up the even more empty jug, now with just 6 1⁄2 tablespoons, and state to the class:

This means only 2.5% of the Earth’s water is truly fresh water.

Measure out 4 1⁄2 tablespoons out of the 6 1⁄2 tablespoons in the gallon jug, pour back into the clear container, and state to the class:

However, 1.7% of the Earth’s water, although it’s fresh, it ISN’T accessible because it’s frozen as glaciers, trapped underground, or otherwise unavailable to humans.

Hold up the gallon just with only 2 tablespoons left and state to the class:

This is all the water, less than 1% on planet Earth that is fresh AND available to sustain all the human, animal, and plant life that has existed, currently exists and will exist in the future.

Peer-to-peer discussion

Teacher-Led discussion: how is water stored and how does it move through Earth? (slides 11-17)

Have students point out where they see water. After they point it out, use the animations to have the different places water is found appear. Then point out that they have categories, such as surface water, groundwater, and water in the atmosphere.

This is how water is stored on Earth. Picture it as a 3D model – it’s in the ground, on the surface, and in the air.

If you teach states of matter, slide 13 would be a good spot to make that connection. This slide can be skipped if states of matter are not part of your lesson.

Model the water cycle (slides 20-24)

Have students draw what they know of the water cycle. Ask them to think about the ways we know water is stored on Earth.

This can be done on a piece of paper or on a whiteboard as a group.

As a class, build a model of the water cycle. It should be simplistic at this point. The model should be available for the class to refer back to throughout the remainder of the unit.

Build it together so that students have a starting point to work from as they develop the models into more sophisticated representations of the water cycle.

DP: Modeling

We think it can be useful for learners to first build a model as a group on a whiteboard. Whiteboards provide a low-risk, flexible way for learners to work together on a challenging task.

Review the components of the water cycle (slide 21)

Because these models will be used throughout the unit, it is important to use common language when discussing the model. See the expandable or the terminology in the Information for Planning & Teaching section.

Water Cycle and Weather Connections (slides 21-28)

The processes of the water cycle are closely tied to weather.

If weather is not an emphasis in your curriculum, skip these slides.

Materials: 2.1 The Hoover Dam & Lake Mead

Assign 2.1 The Hoover Dam & Lake Mead activity

This activity requires learners to read and interpret line graphs. If students are unfamiliar, plan additional time to teach or review the components of graphs.

Materials: Teacher Slides 1.1 Where does the problem exist?

Introduce the problem through an anchoring phenomenon (slides 2-12)

Notes in blue are recommendations for timing. The recommendations offer additional activities or point out areas that can be cut if time is limited.

Notes in purple point out instructional support. For example, if the materials ask students to do a difficult task, a note in purple will guide the instructor through scaffolding that task. they are situated within the instructional sequence to provide in the moment support.