Science Fenns K-5Grades K to 5
A muddy Brazos River bend with a sandy bar on the inside and a cut bank on the outside.

Science / All lessons / Water, Weather and Slow Change

Erosion and Deposition

Carry it away. Drop it somewhere new.

Lesson 27 of 40

Try this first

Before we start

Today’s story

Erosion and Deposition

Rain falls on a bare field. It runs downhill. It picks up soil and carries it to the creek. This is erosion.

Erosion is when water, wind or ice carries sediment from one place to another. When the water slows down, it drops what it carries. That is deposition.

A river bend shows both. The outside bank is cut away. The inside bank piles up sand. Follow the steps.

See it

Five steps. Every time.

    Hands on

    Rain on a Hill

    25 minutes · Do this with a grown-up nearby

    You need

    • Baking pan
    • Soil or sand
    • Cup of water
    • Small stones
    • Grass clippings
    • Paper towel

    Do this

    1. Pile soil at one end of the pan to make a hill.
    2. Pour water gently over the top from a cup.
    3. Watch where the soil goes.
    4. Draw the path of the soil.
    5. Rebuild the hill and cover half with grass clippings.
    6. Pour water again and compare the two sides.
    7. Write what the grass did.
    Write or draw: A drawing of the soil path and a note about the grass.

    Watch for: The bare side loses more soil. The covered side holds better.

    Safety: Do the experiment on a tray outdoors or over a sink.

    Same every time

    Three rules

    Rule 1Erosion moves it.

    Deposition drops it.

    Rule 2Fast water carries more.

    Slow water lets go.

    Rule 3Roots and plants slow erosion.

    Bare soil washes away faster.

    Grandpa Fenn’s notebook

    Say it like a scientist

    erosion
    Moving sediment from one place to another.
    deposition
    Sediment settling in a new place.
    sediment
    Small pieces of rock and soil.
    delta
    Land made where a river drops sediment at its mouth.

    Poppy’s quiz

    Six questions

    Tap an answer. Green means right. You will see why.

    Talk about it

    Say it out loud

    • How do you know water carried the soil?
    • Where near you does a creek or ditch show erosion?
    Did you know

    Where the Mississippi River meets the Gulf of Mexico, dropped sediment has built a huge delta.

    Someone who does this

    A soil conservation expert helps farmers keep soil in place.

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