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Lesson plan Grade 7 Social Studies & Civics

Hoover Dam and the Colorado River: Who Benefits and Who Pays

A grade 7 lesson using Hoover Dam to examine how one shared-river project distributes costs and benefits across nearby and distant communities in the Southwest.

Objectives

  1. Students will explain how building a major dam changes the environment and daily life of nearby places.
  2. Students will explain how the same dam's benefits can extend to distant places through water storage and electricity.
  3. Students will evaluate who bears the costs and who receives the benefits of a shared-river infrastructure project.

Vocabulary

Hydropower
Electricity made from moving water, usually water falling through a dam. It is a renewable power source that can start up quickly when the electric grid needs it.
Reservoir
A human-made lake, usually created by a dam, that stores water for later. Reservoirs supply cities and farms and help control floods.
Watershed
A watershed is all the land where rain that falls will drain to the same stream, river, or lake. Everyone lives in a watershed, no matter how far from the water they live.

Also: displacement, cost-benefit

Teacher overview

Hoover Dam sits on the Colorado River, a river whose watershed reaches across parts of seven Western states, and it was built during the Great Depression to store water and generate hydroelectric power for a region that stretches far beyond the canyon where the dam itself stands. This lesson uses the dam as a concrete case for a question that comes up whenever a community builds shared infrastructure on a river: who benefits from the project, and who bears its costs. A common misconception this lesson addresses is the idea that a project built in one specific place mainly affects only the people who live right there; Hoover Dam's power and stored water reach cities and farms hundreds of miles from the dam itself, while the land flooded to create its reservoir, Lake Mead, changed permanently for the people and ecosystems closest to it.

Procedure

Hook (5 min): Show students a map of the Colorado River watershed stretching across seven states, without labeling the dam yet. Ask: "If a state built a large dam somewhere on this river, which other states do you think it might affect, and why?" Collect two or three predictions on the board.

Direct instruction (15 min): Introduce Hoover Dam using the fact sheet: it was built on the Colorado River during the Great Depression, straddling the border of Nevada and Arizona, and its power plant has a generating capacity of about 2,080 megawatts. Explain that building the dam required flooding a large area of canyon land to create the reservoir behind it, known as Lake Mead, which changed that landscape permanently and displaced the people, plants, and animals that had been there. At the same time, the dam's stored water and electricity extend outward: its power and water-storage benefits reach cities and farms across the Southwest, hundreds of miles from the dam itself, because the river's watershed and the region's electrical grid both connect the dam to places far beyond its immediate location. Note that during the Depression, the dam's construction also created a large number of jobs at a time when jobs were scarce nationwide.

Guided practice (12 min): As a class, begin a two-column decision chart labeled "Nearby effects" and "Distant effects." Fill in the first two rows together: under "Nearby," the flooding of canyon land and the displacement of people and ecosystems near the dam site; under "Distant," electricity delivered to cities far from the dam. Ask students what other rows the chart might need (for example: construction jobs, water storage for farms, changes to the river's natural flow downstream).

Independent/pair practice (13 min): In pairs, students complete the decision chart with at least two more rows on each side, using the fact sheet and the class discussion. Each pair then writes one sentence identifying a group that benefited most from Hoover Dam and one group that bore the greatest cost, with a reason for each.

Closure / exit ticket (5 min): Each student answers independently: "Name one benefit of Hoover Dam that reached a place far from the dam itself, and explain how that benefit traveled that distance." Collect responses to check whether students can explain the connection (the river's watershed, the electrical grid, or both) rather than simply naming a benefit.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

Exit ticket, expected reasoning: A strong answer names either electricity or stored water as the distant benefit and explains the specific connection that carries it: electricity travels through the regional power grid to cities far from the dam, while stored water in Lake Mead is released downstream and distributed through canals and pipelines to farms and cities across the watershed. Accept any answer that identifies a specific benefit and explains the mechanism (grid or river system) that moves it beyond the dam's immediate location, rather than an answer that only states a benefit exists without explaining how it reaches a distant place.

Differentiation

Support (below grade level)

Provide the decision chart with the "Nearby effects" column already filled in, so students focus only on completing the "Distant effects" column using the fact sheet, and provide a word bank (electricity, grid, reservoir, canal, watershed) for the exit ticket.

Extension (above grade level)

Ask students to research, using only the fact sheet provided rather than outside sources, how Hoover Dam's decision-making process might have looked different if the affected states had been required to hold a public vote before construction began, and to write two sentences comparing that hypothetical process to how large infrastructure decisions are made today.

ELL supports

Pre-teach "reservoir," "hydropower," and "displacement" with simple images (a valley before and after flooding; a power line connecting a dam to a distant city). Allow the decision chart to be completed with short phrases or labeled sketches rather than full sentences, and allow the exit ticket to be answered orally if needed.

Extensions

Have students locate a dam or reservoir closer to their own community, if one exists, and identify one nearby effect and one distant effect it has, using a public utility or state agency website as their source.