Unit Plan 20 (Grade 6 Science): Water in Earth’s Systems

Focus: Explain how energy and gravity move water through major Earth reservoirs—oceans, glaciers/ice, and groundwater—as part of the larger water cycle.

Grade Level: 6

Subject Area: Science (Earth & Space Science — Earth Systems & Water Cycle)

Total Unit Duration: 5 sessions (one week), 50–60 minutes per session

I. Introduction

In this unit, students zoom in on where water is stored on Earth and how it moves between oceans, ice, and underground reservoirs. Building on their understanding of the water cycle, they investigate oceans, glaciers/ice sheets, and groundwater/aquifers as key parts of Earth’s systems. Through maps, models, and simple investigations, students explore how energy from the Sun and gravity drive water movement—through currents, melting and flow of ice, and infiltration and groundwater flow. They then create models that show water pathways through these reservoirs, aligned with MS-ESS2-4.

Essential Questions

• Where is most of Earth’s water stored, and how do oceans, glaciers, and groundwater fit into the water cycle?
• How do energy from the Sun and gravity move water through oceans, ice, and underground pathways?
• How can maps and models help us visualize water in Earth’s systems beyond just clouds and rain?
• Why is groundwater important, and how does it connect to surface water and human water use?
• How does understanding water in Earth’s systems help communities make decisions about water resources and hazards (e.g., sea level rise, drought, flooding)?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Identify and describe major water reservoirs on Earth (oceans, glaciers/ice, groundwater, surface water, atmosphere) and how they connect as part of the water cycle.
2. Develop and use models to show how energy and gravity move water between oceans, ice, and groundwater (e.g., evaporation, melting, runoff, infiltration, groundwater flow).
3. Explain how energy from the Sun drives evaporation, surface warming, and density differences that help move water in oceans and surface systems.
4. Explain how gravity pulls water downhill and downward, driving runoff, glacier flow, and groundwater movement in aquifers.
5. Interpret simple maps, diagrams, or data to connect water reservoirs and pathways to real-world issues (e.g., shrinking glaciers, groundwater use, sea level changes).
6. Create a Water in Earth’s Systems Model & Explanation that clearly shows reservoirs, pathways, and driving forces (energy, gravity) within the water cycle.

Standards Alignment — 6th Grade (NGSS-based custom)

• MS-ESS2-4 — Develop a model to describe the cycling of water through Earth’s systems driven by energy and gravity.
  • In this unit: students model how water moves between oceans, glaciers/ice, groundwater, surface water, and the atmosphere, emphasizing how solar energy and gravity drive these movements.

Success Criteria — Student Language

• I can name and locate major water reservoirs on Earth, including oceans, glaciers/ice, groundwater, surface water, and the atmosphere.
• I can draw and label models that show how water moves into and out of oceans, glaciers, and groundwater.
• I can explain how energy from the Sun and gravity work together to move water through Earth’s systems.
• I can use a map or diagram to describe a real-world example (like shrinking glaciers or groundwater use) that connects to water movement.
• I can create a final Water in Earth’s Systems Model & Explanation that someone else can understand and use to see how water moves.