Reading passage Grade 7 Careers & CTE
Inside Pentreath Dam: A Safety Inspector's Week
A grade 7 reading passage following a dam safety inspector through one week at a fictional dam, with a seepage data table and seven comprehension questions.
Objectives
- Students will describe the weekly work of a dam safety inspector and the instruments used.
- Students will cite several details from the passage to support an explanation.
- Students will read a seepage data table and connect it to the text.
Vocabulary
- Spillway
- A dam's overflow channel, giving extra water a safe path around or over the dam when the reservoir gets too full. It protects the dam from being damaged in floods.
Also: seepage, piezometer, gallery, embankment
Teacher overview
Dam safety work is steady and repetitive, and it depends on noticing small changes early. This passage follows an inspector through one week at the fictional Pentreath Dam and includes a short table of seepage readings students must connect to the text. Students often picture dam failure as concrete cracking all at once, so the passage makes clear that much of the trouble an inspector watches for begins as water moving slowly through or under a structure. The questions mix locating stated details with inferences about why the inspector's records matter.
Passage
Pentreath Dam holds back the Norreys River. A reservoir sits behind it, supplying a town and turning a small power unit, while below the dam lies a valley with a road, a school, and about four hundred homes. Jorge Renteria inspects the dam. He has done the job for eleven years, and he says the work is mostly about noticing.
Monday belongs to the instruments. Inside the embankment, which is the earth part of the dam, are narrow pipes called piezometers. Each one measures the pressure of water soaking through the packed soil. Jorge reads them and writes the numbers in a log. He also checks brass markers set into the crest. A survey crew shoots those markers twice a year to see whether any part of the dam has shifted. A shift of half an inch is not a problem by itself, yet a shift that keeps growing year after year is.
Tuesday he walks the gallery. The gallery is a narrow concrete tunnel that runs inside the dam, and it is cold and damp even in July. Jorge carries a flashlight and a piece of chalk. When he finds a crack, he draws a line at each end and writes the date. If the crack passes his chalk marks next year, it is growing. He also looks for wet spots. Given enough time, water works its way through almost any material, and the job is to learn where it is going before it carries soil with it.
Water that works its way through or under a dam is called seepage. A little seepage is normal. Every dam has some. What matters is whether it stays steady and whether it runs clear. Jorge measures it at a small weir near the base, where all of it collects.
| Month | Seepage at the weir (gallons per minute) |
|---|---|
| March | 14 |
| April | 15 |
| May | 16 |
| June | 22 |
Cloudy seepage is the reading an inspector least wants to see. Cloudy water carries soil, and soil leaving a dam means a path is opening inside it. Jorge has seen that once, at another dam, early in his career. Crews worked for two months to fix it.
Wednesday is set aside for machinery. The spillway gates have to lift when a storm fills the reservoir, so they get tested even in a dry month. Jorge runs each gate part of the way up and back down while an operator watches the motor current. He checks the backup generator too. A gate that cannot open during a flood leaves the reservoir with no safe way to release water.
Thursday he sits down with the plant staff and the county emergency manager. They go over the plan for a bad day, including who calls whom, which roads close first, and how long the valley needs to empty. Jorge says the meeting is an uncomfortable one, and that it is the reason the other four days of work matter.
Friday he writes the report. It goes to the state dam safety office, and it lists every reading, every chalk mark, and every gate test. Jorge says the report is the most important thing he does. An inspector who leaves in ten years will read it, compare it to a new reading, and see a pattern that no single week could show.
There is more than one way into this work. Many dam safety engineers hold a four-year civil engineering degree and a state license earned by exam. Inspectors and technicians often come from surveying, construction, or the operating staff of the dam itself, with training paid for by the agency. The people who run the power unit start as operators. Pentreath's unit is small, while the largest hydropower plants operate on a different scale, and the power plant at Hoover Dam has a capacity of about 2,080 megawatts.
Jorge says a dam is never finished. It is a structure that has to be watched for as long as it stands.
Questions
- According to the passage, what does a piezometer measure?
- Why does Jorge draw chalk lines at the ends of a crack and write the date?
- Look at the seepage table. In which month did the seepage rise the most compared with the month before it?
- Explain why cloudy seepage worries an inspector more than clear seepage does.
- Jorge says the report is the most important thing he does. Use two details from the passage to explain why.
- The passage describes more than one route into dam safety work. Name two of those routes and explain how they differ.
- Explain what Jorge means when he says a dam is never finished.
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 pressure of water soaking through the packed soil inside the earth part of the dam. The passage describes piezometers as narrow pipes set into the embankment for that purpose.
- Answer: So he can tell later whether the crack has grown. If the crack passes his marks the next year, it is getting longer, which the dated chalk lines make visible.
- Answer: June. Seepage rose by one gallon per minute in April and again in May, then rose by six gallons per minute in June, which is the largest jump in the table.
- Answer: Because cloudy water is carrying soil out of the dam. The passage explains that soil leaving a dam means a path is opening inside it, which is how a structure begins to fail.
- Answer: Accept any two supported details. Sample response: the report goes to the state dam safety office and records every reading, and an inspector arriving ten years later can compare it to new readings and see a pattern that no single week could show.
- Answer: Accept any two of the three routes. Engineers usually earn a four-year civil engineering degree and a state license by exam, inspectors and technicians often come from surveying, construction, or the dam's own operating staff with agency-paid training, and power unit staff start as operators. The routes differ in how much schooling comes before the job and how much training happens on it.
- Answer: He means the dam must be watched for as long as it stands. Building it was not the end of the work, because seepage, cracks, and movement can appear at any time and only regular inspection catches them.
Differentiation
Support
Read the first three paragraphs aloud while students follow along, then let them read the rest independently. Provide a labeled cross-section drawing showing the reservoir, the embankment, the gallery, and the weir so the vocabulary has a picture attached. Allow question 5 to be answered with one cited detail instead of two.
Extension
Ask students to write the short paragraph Jorge would add to his Friday report about the June seepage reading. The paragraph must state what changed, name one possible explanation drawn from the passage, and say what he would check next. Students should not introduce facts the passage does not supply.
ELL supports
Pre-teach "seepage," "gallery," and "spillway" with pictures and a gesture for each. Give students a two-column glossary sheet to fill in as they read, with the term on one side and their own words on the other. Allow questions 1 through 3 to be answered by pointing to and copying the sentence or table row that holds the answer.
Extensions
Have students compare the inspection routine in this passage with the routine for something else that is watched over long periods, such as a bridge, a school roof, or a levee. Students list what would be measured, how often, and what a rising trend would mean, then write one sentence on what all long-term inspection jobs have in common.