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Runoff, Infiltration, and Groundwater

Grade 5 Earth & Space Science — Water on Earth Systems | Unit 1, Lesson 4 of 6

📚 Grade: 5th Grade⏱️ Duration: 45–60 minutes🔬 Subject: Earth & Space Science — Water on Earth Systems
🏞️💧
Water can move over land or into the ground.
📋 NGSS Standard:
5-ESS2-1 — Develop a model using an example to describe ways the geosphere, biosphere, hydrosphere, and/or atmosphere interact.

🎯 Learning Objective

Students will compare runoff and infiltration and explain how water can move across land or into the ground.

💡 The Big Idea

When water falls on land, some runs over the surface and some soaks in. Both paths are important parts of Earth’s water system.

🔬 The Science

Science Snapshot
Runoffmoves across surfacefast on hard groundcan carry sedimentInfiltrationmoves into soilslower storagefeeds groundwatercompare
Surface water and underground water are connected parts of one moving system.

What is happening?

When water reaches the ground, some of it runs across the surface and some of it soaks into the spaces between soil particles and rocks. That soaking-in process is called infiltration, and stored underground water is called groundwater.

Why it works that way

Runoff is more likely on steep slopes, packed soil, pavement, or already-saturated ground. Infiltration is more likely when soil has open pore spaces and time to absorb the water. Gravity then helps underground water move slowly through connected spaces.

Look for this in the lesson

Students should compare surfaces and ask why the same rainstorm can behave differently in a forest, a garden bed, and a parking lot. The lesson gets stronger when they explain what controls the path the water takes.

Ask while you read: What makes water run off in one place but soak in somewhere else?

📦 Materials

🏠 Household Items to Gather

📋 Printables

🧪 Investigation

Step 1 — Build two surfaces (10 min)
Set up one surface that absorbs water well and one that does not.
Step 2 — Add water slowly (10 min)
Observe whether the water runs off or soaks in.
Step 3 — Compare the paths (10 min)
Record what happened on each surface.
Step 4 — Connect to real landforms (10 min)
Discuss roads, grass, hills, and bare soil.
Step 5 — Explain groundwater (10 min)
Students describe where infiltrated water can go next.

💬 Discussion Questions

What is runoff?Water moving over the land surface.
What is infiltration?Water soaking into the ground.
Why might pavement increase runoff?Water cannot soak in easily.

🚀 Extensions

Extension: Compare a patch of grass and a hard surface outside after rain and look for signs of runoff.

👩‍🏫 Parent/Teacher Notes

Teaching move: Students often think underground water disappears. Reinforce that it is still part of the water system.

Student Worksheet

Name: ________________________     Date: ________________________

1️⃣ Compare the surfaces

SurfaceMostly runoff or infiltration?Evidence
Absorbing surface
Less absorbing surface

2️⃣ Explain what groundwater is

🔑 PARENT ANSWER KEY — Detach before giving worksheet to students

Sample Explanation

Runoff moves across the surface, while infiltration soaks into the ground. Infiltrated water can become groundwater.

✅ What Success Looks Like