Worksheet Grade 4 English Language Arts
Hoover Dam's Power Plant: A Grade 4 Reading and Vocabulary Worksheet
A grade 4 worksheet built on a short passage about Hoover Dam, mixing literal, vocabulary, and inference questions about how the dam makes power.
Objectives
- Students will locate stated facts about Hoover Dam directly in a short informational passage.
- Students will use context clues in the passage to explain the meaning of the words reservoir and turbine.
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.
- Turbine
- A machine with blades that spin when water rushes past, like a high-tech waterwheel. Spinning turbines turn generators that make electricity.
Also: hydroelectric, generate
Teacher overview
Hoover Dam is a real dam that blocks the Colorado River on the border of Nevada and Arizona. This worksheet gives students a short passage about the dam and its power plant, then asks them to practice three reading skills at once: finding facts stated directly in the text, using context clues to figure out unfamiliar words, and making an inference about why the dam sits where it does. The passage stays close to a single real number, the most power the dam's plant can generate, so the worksheet also gives students practice reading a number correctly inside a sentence.
Student Worksheet
Read the passage, then answer the questions below.
Hoover Dam blocks the Colorado River. It sits in a deep canyon on the border of Nevada and Arizona. Behind the dam, the river backs up. It forms a huge lake called a reservoir. Water from the reservoir flows out through openings low in the dam. The water rushes downward fast. It spins big machines called turbines. Each turbine connects to a generator. A generator turns the spinning motion into electricity. Power made this way, from moving water, is called hydroelectric power. Hoover Dam's power plant can generate about 2,080 megawatts of hydroelectric power. That is enough to help supply homes and businesses in three states. Years of drought have lowered the water in the reservoir, though, so the plant has been generating less power than it did in wetter years. Engineers picked this deep, narrow canyon on purpose. Its steep rock walls hold back the reservoir. The dam wall does not need to be very long. The huge reservoir also stores enough water to keep water moving through the turbines all year.
- What river does Hoover Dam block?
- In your own words, what is a reservoir?
- What happens to the water right before it spins a turbine?
- About how many megawatts of power can the plant generate?
- Find the word "hydroelectric" in the passage. What does this word mean?
- Why do you think engineers picked a deep, narrow canyon for this dam?
- Name the two machines that work together to turn moving water into electricity.
- The dam's power reaches homes in three states. What does that tell you about how much power it makes?
- Write one sentence using the word "generate."
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 Colorado River. The first sentence of the passage states directly that Hoover Dam blocks the Colorado River.
- Answer: A reservoir is a lake formed when a river's water is trapped behind a dam. The passage explains that behind the dam the river backs up and forms a huge lake called a reservoir.
- Answer: The water is let through openings low in the dam and rushes downward. The passage states this happens right before the water spins the turbines.
- Answer: About 2,080 megawatts. The passage states this number directly when describing what the power plant can generate. This is the plant's rated capacity, the most it can make; the Bureau of Reclamation reports that drought and low water in Lake Mead, the dam's reservoir, have cut its actual power generation by about 30 percent.
- Answer: Hydroelectric means power made from moving water. The sentences right before the word explain that turbines are spun by rushing water and connected to generators, and the next sentence names that kind of power "hydroelectric."
- Answer: Answers will vary but should reference that steep canyon walls can hold back a large reservoir without requiring a very long dam wall, details stated directly near the end of the passage.
- Answer: A turbine and a generator. The turbine spins from the rushing water, and the generator, connected to the turbine, turns that spinning motion into electricity.
- Answer: It tells the reader the dam produces a large amount of power, since supplying homes and businesses across three states requires far more electricity than a single town would use.
- Answer: Answers will vary but must use "generate" to mean produce or make, for example: "Wind can also generate electricity when it spins a different kind of turbine."
Differentiation
Support
Read the passage aloud once as a class before students work independently, and provide a simple labeled diagram (river, dam, reservoir, turbine, generator) alongside the text for students to reference while answering questions 2, 3, and 7.
Extension
Ask students to use details from the passage to write two sentences explaining why hydroelectric power keeps working even on a cloudy or windless day, unlike some other kinds of power.
ELL supports
Pre-teach "dam," "reservoir," and "turbine" with a simple sketch of each before students read the passage, and allow question 2 and question 9 to be answered orally and then transcribed by a partner or aide for students still building written English fluency.