Work of Water — Erosion Experiments

Water never stops working. Children who've built sand castles have felt this — but the stream tray makes the lesson systematic. They see erosion carve channels, sediment settle into deltas, pebbles smoothed by tumbling.

• Framework: Montessori
• Unit: Cultural Studies
• Learning area: Physical Science
• Level: Ages 6-7

Objectives

• Observe how water shapes the Earth through erosion, transport, and deposition
• Conduct simple experiments with a stream tray
• Understand rivers, deltas, and coastlines as products of water's work
• Connect to geography and the water cycle

Materials

• Shallow tray with a slope (stream tray)
• Sand, pebbles, and soil
• Pitcher of water
• Food coloring (optional)
• Small paper boats

Instructions

1. Set up the tray with a slope and fill the top end with sand and soil. 2. Pour water slowly at the top. 3. Observe channels forming. 4. Pour faster and watch erosion speed up. 5. Note where sediment settles (the delta). 6. Add pebbles and observe how they resist erosion. 7. Sketch the changes. 8. Discuss: What does this look like in real rivers? 9. Connect to maps — find the deltas of the Nile, Mississippi, Ganges.

Educator tip

Let the children pour the water. The mess is the lesson. Protect floors with a tarp.

Assessment

Note observation accuracy, connections drawn between experiment and real geography, and extensions children invent.

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