This lesson focuses on the availability of freshwater on Earth. Students review the basic terms and processes associated with the water cycle, play a game to determine the percentage of the Earth’s surface covered by water, work together in groups to estimate the distribution of water in the various locations on Earth where it is found, and discover how much fresh water is available on Earth for human use.

Focus Questions

Students answer these essential questions: 

Where is water found on Earth? 

How does water move on Earth? 

Is there enough water on Earth for everyone? 

Why are the Great Lakes unique?

Subject/Target Grade

Science and Social Studies/Middle School (6-8)

Duration

One or two 50-minute periods – Classroom & outdoor setting

Materials

per class

• 3 100-ml graduated cylinders

• container of water (10-ml/student)

• Water Cycle with no labels (transparency master) 

• Water Cycle with arrows and locations correctly labeled (transparency master) 

• cup of salt water (optional, for one student to taste)

• map of the United States

• 1 green and 1 blue paper plate (optional)

• 1-2 inflatable globes

• blue food coloring

• 1 clear plastic 2-L (2000 ml) bottle filled with (blue) water

• 5 clear plastic 9 oz. or 12 oz. cups

• permanent marker

• 1 water dropper

• paper towels

• scissors

• Where Is Water on Earth? (transparency master/answer key) 

• How Much of Earth’s Water Is Available for Human Use? (transparency master) 

• Great Lakes Physical Features and Population (transparency master) per small group 

• 1 clear plastic 2-L (2000ml) bottle

• 100-ml graduated cylinder

• 5 clear plastic 9 oz. or 12 oz. cups

• 1 water dropper

• calculator

• 1 green and 1 blue paper plate (optional)

• scissors (optional)

• Water Cycle with no arrows or labels (student activity) 

• Where Is Water on Earth? (student activity) 

• map of the United States or Great Lakes watershed map

• sidewalk chalk

• Water Cycle Scavenger Hunt (outdoor activity)