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Quiz & test questions Grade 8 English Language Arts

Why the Fallowmead Canal No Longer Flows Downhill

A 30-point grade 8 ELA unit test on a fictional text about a sinking farm valley, mixing multiple choice, short answer, and one explanatory paragraph.

Objectives

  1. Students will identify the cause and effect chain in an informational text.
  2. Students will cite the sentence that most strongly supports an inference about the canal.
  3. Students will write an explanatory paragraph for a stated audience using text details.

Vocabulary

Aquifer
An aquifer is an underground layer of rock, sand, or gravel that holds water in the tiny spaces between its grains. Wells reach down into aquifers to bring water up to the surface.

Also: clay, compaction, subsidence, gravity

Teacher overview

This assessment is worth 30 points and runs about 45 minutes. Students read one fictional informational text and answer four multiple-choice items worth 2 points each, five short-answer items worth 3 or 4 points, and one explanatory paragraph worth 6 points. The text is organized as a cause and effect chain with one step that students often skip, which is that the ground itself can lose thickness. Several items turn on the difference between water leaving the aquifer and the aquifer losing the space that held it.

Why the Fallowmead Canal No Longer Flows Downhill — Grade 8 English Language Arts
Name: ____________________________ Date: ______________

Assessment

Read the fictional text below, then answer every item. Fallowmead Valley and its irrigation district were invented for this test.

The Canal That Stopped Running Downhill

Farmers dug the Fallowmead Canal in 1928. It carries river water forty miles across the valley to farms that would otherwise have none. The canal has no pumps in it. It works on gravity, dropping about one foot every mile, which is just enough tilt to keep water moving in one direction.

The canal was never the only source of water. Farms drill wells into the aquifer under the valley, and in dry years they pump harder, because the river carries less. The aquifer is not an open cave. It is layers of sand and gravel that hold water in the spaces between grains, with layers of clay pressed between them.

Those clay layers are the part of the story most people miss. When water is pumped out of the sand faster than rain and snowmelt refill it, the water pressure in the ground falls. The weight of everything above does not change, so the clay layers slowly squeeze together. As they compact, the land surface above them drops. Engineers call that sinking subsidence.

Surveyors have measured the valley since 1960. Some sections have dropped a few inches. Two sections south of the highway have dropped several feet. The land did not sink evenly, and that is what broke the canal.

A canal built to drop one foot per mile cannot afford to lose its tilt. Near the town of Fallowmead, the ground under one stretch sank more than the ground downstream of it. Water there now moves slowly and pools after storms. In 2019 the district installed a pump to push water through that stretch, and it has run every irrigation season since.

The clay will not spring back. Once those layers compact, the space that held water is gone for good, so the aquifer can never store as much again, no matter how wet the next winter is. The district now sets a yearly pumping limit, measures ground level twice a year, and fills two recharge basins with river water in wet years to slow the decline.

  1. (2 points) The main idea of this text is that
    A. canals should always be built with pumps.
    B. pumping groundwater changed the land, and the changed land broke the canal.
    C. the Fallowmead Canal was poorly designed in 1928.
    D. farms in the valley should stop irrigating.
  2. (2 points) Which sentence best supports the idea that the damage to the aquifer cannot be reversed?
    A. "Surveyors have measured the valley since 1960."
    B. "The canal has no pumps in it."
    C. "Once those layers compact, the space that held water is gone for good."
    D. "In 2019 the district installed a pump to push water through that stretch."
  3. (2 points) In this text, "subsidence" most nearly means
    A. water soaking into the ground.
    B. the sinking of the land surface.
    C. the drying of a riverbed.
    D. the repair of a canal.
  4. (2 points) The text is organized mainly by
    A. comparing two valleys.
    B. listing events in order of importance.
    C. tracing a chain of causes and effects.
    D. describing a place from north to south.
  5. (3 points) Explain why the clay layers, rather than the sand layers, are described as the part of the story most people miss. Quote the sentence that most strongly supports your answer.
  6. (3 points) The canal drops about one foot per mile. Explain why that detail matters to the rest of the text, using evidence from the passage.
  7. (3 points) Why did the district install a pump in 2019? Answer in one or two sentences using details from the text.
  8. (3 points) A reader says the valley's problem would be solved by one very wet winter. Correct that statement using evidence from the text.
  9. (4 points) The text says the land did not sink evenly. Explain why uneven sinking caused more trouble for the canal than even sinking would have.
  10. (6 points) Write an explanatory paragraph of five to seven sentences for the district's newsletter telling farmers why the canal now needs a pump. Use at least two details from the text.

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

Answer Key
  1. Answer: B. The text traces pumping to falling pressure, to compacting clay, to sinking land, and finally to a canal that no longer carries water by gravity alone.
  2. Answer: C. That sentence states directly that the storage space is gone for good, while the other choices report measurements, design, or a repair.
  3. Answer: B. The text defines the term right after describing the land surface dropping as the clay layers compact.
  4. Answer: C. Each paragraph adds a link in a chain, from pumping to pressure to compaction to the canal's lost tilt.
  5. Answer: Because the sand holds the water people pump, readers watch the sand, while the clay is what loses thickness and lowers the land. Supporting sentence: "As they compact, the land surface above them drops." Also accept "The weight of everything above does not change, so the clay layers slowly squeeze together." Award full credit for a correct quotation with an explanation that connects clay to the sinking.
  6. Answer: It shows how little tilt the canal has to work with. Because the drop is only about a foot per mile, a stretch of ground that sinks even slightly more than the ground downstream of it can flatten the slope, and the text says water there now moves slowly and pools after storms.
  7. Answer: Because the ground under one stretch near Fallowmead sank more than the ground downstream, so water no longer moved through it on its own. The pump pushes water through that flattened stretch, and it has run every irrigation season since.
  8. Answer: The text says the clay will not spring back and that the space which held water is gone for good, no matter how wet the next winter is. A wet winter could add water to the sand layers, but it cannot restore the storage the compacted clay lost.
  9. Answer: A canal depends on a steady slope from one end to the other. If the whole valley sank by the same amount, the tilt between any two points would stay the same and water would keep moving. Because two sections dropped several feet while others dropped a few inches, one stretch ended up lower than the ground downstream of it, which flattened or reversed the slope and left water standing.
  10. Answer: Accept any paragraph of five to seven sentences that is accurate and uses at least two details from the text. A full-credit response explains that heavy pumping lowered pressure in the aquifer, that the clay layers compacted and the land sank unevenly, that the canal's one-foot-per-mile drop was lost in one stretch, and that the district installed the pump in 2019 for that reason. Deduct for statements the text contradicts, such as claiming the sinking can be undone.

Differentiation

Support

Give these students the fictional text with its five stages numbered in the margin and a blank cause and effect chain to fill in before answering. Reduce item 10 to four sentences and provide a paragraph frame that begins with the pumping and ends with the pump.

Extension

Ask students to write the two-paragraph letter the fictional district would send to a farmer who objects to the yearly pumping limit, using only evidence from the text and acknowledging one fair point the farmer could raise.

ELL supports

Pre-teach "canal," "clay," "compact," and "sink" with a labeled cross-section drawing of the fictional valley before and after the land dropped. Allow items 5 through 8 to be answered in two sentences, and permit item 10 to be drafted as a spoken response first.

Extensions

Students compare the fictional text with a one-paragraph summary they write for a local news site, then list two details they cut and explain why a news reader does not need them.