Little Lab Coats logo
Little Lab Coats

Where Is Earth’s Water?

Grade 5 Earth & Space Science — Water on Earth Systems | Unit 1, Lesson 1 of 6

📚 Grade: 5th Grade⏱️ Duration: 45–60 minutes🔬 Subject: Earth & Space Science — Water on Earth Systems
🌎💧
Most of Earth’s water is in the ocean, not in easy-to-use fresh water.
📋 NGSS Standard:
5-ESS2-2 — Describe and graph the amounts and percentages of water and fresh water in various reservoirs to provide evidence about the distribution of water on Earth.

🎯 Learning Objective

Students will describe where most of Earth’s water is found and compare salt water with fresh water reservoirs.

💡 The Big Idea

Most of Earth’s water is in the ocean. Only a small fraction is fresh water, and even less is easy for humans to use.

🔬 The Science

Science Snapshot
Most water on Earthsalty oceansnot for drinkinglargest storeFreshwaterice + glaciersgroundwatertiny surface sharecompare
The same water can be stored in different places, but the amount and usefulness of each reservoir are very different.

What is happening?

Earth is often called a water planet, but most of that water is not easy for people, plants, or many animals to use. About 97 percent is salty ocean water, and most freshwater is locked in ice or stored underground.

Why it works that way

That means the small amount of water in lakes, rivers, soil, air, and living things matters a lot. Scientists track where water is stored because the location of water affects weather, habitats, farming, and drinking-water supplies.

Look for this in the lesson

Students should notice that “a lot of water” is not the same as “a lot of usable freshwater.” This lesson works best when children compare major water reservoirs and talk about why some stores are harder to access than others.

Ask while you read: Which water stores are biggest, and which ones are easiest for humans and ecosystems to use?

📦 Materials

🏠 Household Items to Gather

📋 Printables

🧪 Investigation

Step 1 — Identify water reservoirs (10 min)
List the places where water can be found on Earth.
Step 2 — Compare big vs small shares (10 min)
Use a simple model with 100 counters or a pie chart to compare ocean water and fresh water.
Step 3 — Find accessible fresh water (10 min)
Discuss why only some fresh water is easy to use.
Step 4 — Record the pattern (10 min)
Students explain where most water is stored.
Step 5 — Reflect on importance (10 min)
Discuss why fresh water is valuable even though Earth has lots of water overall.

💬 Discussion Questions

Where is most of Earth’s water found?In the ocean.
Why is fresh water especially important?Living things and people depend on it.
Why is not all fresh water easy to use?Some is frozen or underground.

🚀 Extensions

Extension: Look up where your community gets its water and connect it to a reservoir like groundwater or surface water.

👩‍🏫 Parent/Teacher Notes

Teaching move: Students often hear “Earth is mostly water” and assume water is abundant everywhere. Use the reservoir comparison to challenge that idea.

Student Worksheet

Name: ________________________     Date: ________________________

1️⃣ Water reservoirs

ReservoirSalt water or fresh water?Large or small share?
Ocean
Glaciers
Groundwater
Lakes and rivers

2️⃣ What is the main pattern?

🔑 PARENT ANSWER KEY — Detach before giving worksheet to students

Sample Pattern

Most of Earth’s water is salt water in the ocean. Only a small fraction is fresh water, and only a tiny part of that fresh water is easy for humans to use at the surface. Students should not confuse “fresh water exists” with “fresh water is widely available.”

✅ What Success Looks Like