5-ESS2-2: Graphing Earth's Salt and Fresh Water
Also called NGSS 5-ESS2-2 · Topic: Earth's Systems · Earth and Space Science
The Official Wording
Describe and graph the amounts of salt water and fresh water in various reservoirs to provide evidence about the distribution of water on Earth.
Assessment boundary: Assessment is limited to oceans, lakes, rivers, glaciers, ground water, and polar ice caps, and does not include the atmosphere.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What 5-ESS2-2 Means in Plain English
Fifth graders find out how much of Earth's water is salty and how much is fresh, and where each kind is stored. They graph the amounts in oceans, ice caps and glaciers, groundwater, lakes and rivers, then use the graph to explain why usable fresh water is scarce.
Water vapor in the air is left out, so the graph covers only water on and under the ground. This builds on finding water as ice and liquid (2-ESS2-3) and leads to modeling the water cycle in middle school (MS-ESS2-4).
5-ESS2-2 I Can Statements
- I can tell which places on Earth hold salt water and fresh water.
- I can make a bar graph of where Earth's water is stored.
- I can use my graph to explain why fresh water is precious.
5-ESS2-2 Worked Example
A tabletop model that shrinks all of Earth's water down to one liter, using a medicine syringe, small cups and an eyedropper.
If all of Earth's water fit in a one-liter bottle, how much would sit in each place?
Set It Up: A one-liter bottle of water, a measuring cup marked in milliliters, a 10 mL medicine syringe, an eyedropper, a spoonful of salt and four clear cups labeled Ocean, Ice caps and glaciers, Groundwater, and Lakes and rivers.
- Measure 975 mL into the Ocean cup and stir in the salt.975 mL of salt water, nearly the whole bottle
- Look at what is left in the bottle. That 25 mL stands for all the fresh water.25 mL, about five teaspoons
- Use the syringe to move 17 mL into the Ice caps and glaciers cup.17 mL locked up as ice
- Move 7.5 mL into the Groundwater cup.7.5 mL stored in soil and rock
- Squeeze one drop from the eyedropper into the Lakes and rivers cup, then graph all four cups on one scale.One giant bar, two short bars, one bar too small to see
Nearly all the water, 975 of 1,000 mL, is salty ocean water, and most fresh water is ice or groundwater, so lakes and rivers get a single drop.
Why it works: Oceans fill huge, deep basins that cover most of Earth's surface, while fresh water comes from rain and snow, and much of it stays frozen near the poles or soaks into the ground.
Common Mistakes with 5-ESS2-2
Thinking most water is fresh
“There's so much water, we can never run out of drinking water.”
Try this: Look at the 975 mL ocean cup. Salt water needs its salt removed before people can drink it or water crops.
Forgetting groundwater
A graph with bars for oceans, lakes and ice but none for water underground
Try this: Rain soaks into soil and rock. Groundwater holds far more fresh water than all lakes and rivers combined, so it needs its own bar.
Stretching tiny bars
Lakes and rivers drawn as a bar the same height as groundwater
Try this: Use one scale for every bar. If a bar is too tiny to see, label it with its amount instead of drawing it bigger.
Where 5-ESS2-2 Fits
Practice 5-ESS2-2
Quick Check
- Where is most of Earth's water?
- Where is most of Earth's fresh water stored?
- Why do lakes and rivers get such a tiny bar on the graph?