Lesson plan Grade 4 English Language Arts
Bends in the Kestrel River: A Grade 4 Erosion Writing Lesson
A grade 4 lesson where students read a labeled river diagram, identify the causes of a growing river bend, and write an informative paragraph with grouped ideas.
Objectives
- Students will identify at least two causes of erosion on the outside bank of a river bend from a labeled diagram.
- Students will write an informative paragraph that groups causes in one part and effects in another part.
Vocabulary
- Erosion
- Erosion is the wearing away and carrying off of soil and rock by moving water, wind, or ice. Fast-moving stormwater can strip soil from bare ground and stream banks.
Also: outside bank, inside bank, current, informative
Teacher overview
The Kestrel River, a river invented for this lesson, curves around a low hill on its way to a reservoir, and the curve has grown wider every year for as long as the fictional town beside it can remember. This lesson uses a labeled diagram of that one bend to give students a concrete, visual case for a common land-shaping process: fast-moving water erodes the outside of a curve while slow-moving water drops sediment on the inside of the same curve. Students then write an informative paragraph that groups the causes of the erosion separately from its effects, practicing the paragraph structure that CCSS W.4.2 expects. A common misconception this lesson addresses is that a river erodes its banks evenly all the way around a bend; the diagram makes clear that erosion and deposit happen on opposite sides of the same curve for a specific, explainable reason.
Procedure
Hook (5 min): Show students a simple hand-drawn river bend on the board with an arrow showing the direction of flow. Ask: "If you dropped a stick in the water at the top of this bend, which side of the curve do you think it would hit first, the inside or the outside?" Collect a few guesses without confirming an answer.
Direct instruction (12 min): Distribute the labeled Kestrel River diagram handout, which shows the outside bank (steep, bare soil, arrows showing fast current) and the inside bank (gentle slope, a strip of sand, arrows showing slow current). Read the two labeled captions aloud together: "Fast water on the outside bank carries soil away," and "Slow water on the inside bank drops sand it was carrying." Model orally combining these two captions into one cause-and-effect sentence: "Because the water moves fast against the outside bank, it carries soil away and makes that bank steeper every year."
Guided practice (10 min): In pairs, students find one more detail on the diagram (a fallen tree root exposed on the outside bank, a new sandbar forming on the inside bank) and write one sentence explaining what caused it, using the sentence frame "Because the water ___, the ___." Two or three pairs share their sentence aloud.
Independent writing (15 min): Students draft an informative paragraph titled "Why the Kestrel River's Bend Keeps Growing." The paragraph must have two clearly grouped parts: first, the causes (how fast and slow water behave differently on each side of the bend), and second, the effects (a steeper outside bank, a growing sandbar on the inside bank). Students may use the diagram and their guided-practice sentence as source material.
Closure / formative check (8 min): Students trade paragraphs with a partner and complete one check: underline the sentence where the writer switches from causes to effects. Then ask the whole class the formative question, "What is one detail from the diagram that belongs in the causes part of your paragraph, and one that belongs in the effects part?" Cold-call two students to confirm the grouping is landing correctly before dismissal.
Student Handout
The Kestrel River diagram (draw or print one per student)
Draw the Kestrel River from above as one wide curve bending around a low hill. Put a large arrow in the water pointing downstream so students can see which way the river flows. Label the two banks:
- Outside bank: a steep bank of bare soil with a tree root sticking out of it where soil has washed away. Draw long arrows in the water beside it and label them "fast current." Caption: "Fast water on the outside bank carries soil away."
- Inside bank: a gentle slope with a strip of sand along the water and a new sandbar forming at the edge. Draw short arrows in the water beside it and label them "slow current." Caption: "Slow water on the inside bank drops sand it was carrying."
Answer these after your teacher reads the two captions aloud.
- What is the water doing on the outside bank, and what does it do to that bank over time?
- What is the water doing on the inside bank, and what does it build there over time?
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
- Answer: The outside bank has fast-moving water, which carries soil away and makes that bank steeper and taller over time.
- Answer: The inside bank has slow-moving water, which drops the sand and soil it was carrying, building a sandbar that grows outward over time.
- Formative check answer: A cause-part detail is the different speeds of water on each side of the bend; an effect-part detail is the steeper outside bank or the growing inside sandbar.
Differentiation
Support
Provide a partially written paragraph with the causes section already drafted, so students only need to compose the effects section, and offer the sentence frame "Because the water ___, the ___" for every sentence rather than only the guided-practice step.
Extension
Ask students to add a third paragraph part predicting what the Kestrel River's bend might look like in twenty more years if nothing changes, using the same cause-and-effect reasoning they used for the current bend.
ELL supports
Pre-teach "erosion," "outside bank," and "inside bank" with the diagram itself as the visual support, tracing each term with a finger on a printed copy before the lesson begins. Allow the independent paragraph to be written as two labeled lists (Causes / Effects) instead of full paragraph prose for students still building sentence-level English fluency.