Lesson plan Grade 3 Social Studies & Civics
Two Rivers Dam Then and Now: A Grade 3 Place-Change Lesson
A 45-minute grade 3 social studies lesson where students compare the fictional town of Two Rivers before and after a dam and explain how the place changed.
Objectives
- Students will explain how building a dam changed the town of Two Rivers over time.
- Students will name two ways people changed the river to meet the town's needs.
- Students will sort changes into what the town gained and what it lost.
Vocabulary
- Dam
- A strong wall built across a river to hold back water. Dams store water for people and farms, help prevent floods, and can make electricity.
- Reservoir
- A human-made lake, usually created by a dam, that stores water for later. Reservoirs supply cities and farms and help control floods.
Teacher overview
Two Rivers (a fictional town used for this lesson) sits where two small rivers meet in a valley. Long ago the town had trouble in dry months, because the rivers ran low and there was no way to store water. People built a dam across the wider river, which held the water back and formed a reservoir, a human-made lake. This lesson uses that one change to teach two social studies ideas together: how people change their environment to meet a need, and how a place can look and work very differently over time.
Procedure
Hook (5 min): Post the two large picture cards side by side. The Before card shows two narrow rivers, a few farms, and a dry riverbed in summer. The After card shows a tall dam, a wide reservoir behind it, boats on the lake, and green fields. Ask the class one question: what do you think changed here, and why might people have wanted that change?
Direct instruction (15 min): Explain that a dam is a strong wall people build across a river to hold water back, and that the water that collects behind it forms a reservoir. Tell the story of Two Rivers in plain steps. Before the dam, the town ran short of water every dry summer. People decided to build a dam so the reservoir could store water from the wet months and let it out slowly all year. The dam also made electricity as water passed through it, and it held back floods in heavy rains. Point out one hard part too: the rising reservoir covered some low farmland and an old road, so a few families had to move. Note that towns in dry and flood-prone regions around the country have made similar choices for generations.
Guided practice (12 min): Give each small group a set of change cards (steady water all year, a lake for boating, electricity for homes, farmland lost under the lake, an old road covered, fewer dry-summer worries). Groups place each card on chart paper under one of two headings the teacher writes: What the Town Gained and What the Town Lost. Groups then talk about which change they think mattered most to the people of Two Rivers.
Independent practice (8 min): Each student writes two or three sentences explaining how the dam changed Two Rivers over time. Students must use the words dam and reservoir at least once and name one thing the town gained.
Closure and exit ticket (5 min): Students answer one question on an index card: "Name one way the town of Two Rivers changed after the dam was built, and say whether it was a gain or a loss." Collect the cards and scan them for the core idea, that the dam and its reservoir changed how the town stored and used water, before students leave.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
Guided practice answer: Gains include steady water all year, a lake for boating, electricity for homes, and fewer dry-summer worries. Losses include farmland covered by the reservoir and an old road that went under the water. Groups may reasonably rank steady water as the change that mattered most, since the town first built the dam to solve its dry-summer water shortage.
Exit ticket answer: Any answer that names a real change and labels it correctly. Examples: the reservoir gave the town steady water all year (gain), or some farmland was covered by the lake (loss). Look for a clear change tied to the dam or reservoir rather than a general statement.
Differentiation
Support
Give these students a change card set with the Gained and Lost sorting already started, so one card sits under each heading as a model before they place the rest. Allow the independent writing to be a single sentence that names one change and whether it was a gain or a loss.
Extension
Ask students to add one change card of their own that the class did not discuss, such as new jobs building the dam or a park by the lake, and to explain in writing whether it belongs under Gained or Lost and why.
ELL supports
Pre-teach dam, reservoir, and change over time with a simple side-by-side drawing of a river before and a reservoir after. Allow students to sort the change cards and explain their thinking by pointing and speaking, rather than in full written sentences.