Graphic organizer Grade 11 English Language Arts
Three Records of the Drayhollow Cloudburst: A Synthesis Matrix
A grade 11 synthesis matrix that sets a rain-gauge log, a public works memo, and three resident accounts against five sub-questions about one flooded street.
Objectives
- Students will record what each of three sources says about the same sub-question.
- Students will distinguish agreement between sources from repetition of a single source.
- Students will state a supportable claim and name the sub-question their sources cannot settle.
Vocabulary
- Storm drain
- A storm drain is the grate at the edge of a street that swallows rainwater and sends it through pipes to the nearest creek or river. That water is usually not treated, so only rain belongs down the drain.
Also: synthesis, sub-question, corroboration, inlet, rainfall intensity
Teacher overview
This organizer is a synthesis matrix: five sub-questions run down the left side, three sources run across the top, and a final column asks what the row as a whole will support. It is built to interrupt the source-by-source paragraph, in which a writer summarizes the first source, then the second, then the third, and calls the result synthesis. A matrix read across a row instead of down a column produces the sentence a reader wants, a statement of what the sources together establish. One misconception about the water content is worth correcting before students read: many students believe that storm drains carry street runoff to the wastewater treatment plant. In a separate storm sewer system, which is what most newer neighborhoods have, the inlet on the corner discharges to the nearest creek with no treatment at all, and that fact changes what a reader should conclude about the leaves and oil that wash off a street.
Organizer
The broad question. Why did Drayhollow Row flood on the night of May 19 when Weald Street, one block over, did not?
Source notes. The town of Ledstow, Drayhollow Row, and every reading below are fictional and were written for this organizer.
Source A. Rain gauge log, Ledstow public works yard, May 19.
| Clock time | Rain in that 15 minutes |
|---|---|
| 8:00 to 8:15 p.m. | 0.11 inch |
| 8:15 to 8:30 p.m. | 0.94 inch |
| 8:30 to 8:45 p.m. | 1.32 inches |
| 8:45 to 9:00 p.m. | 0.38 inch |
| 9:00 to 9:15 p.m. | 0.06 inch |
Source B. Memo from the Ledstow public works director, May 22. The Drayhollow Row storm sewer was designed to carry the runoff from a storm that drops about one inch in an hour. The line discharges to Skelmere Brook and receives no treatment. Two of the four inlets on the block were found packed with leaf litter on the morning of May 20. Weald Street sits about six feet higher and drains toward a grassed swale rather than a piped inlet.
Source C. Three statements recorded at the neighborhood meeting on May 27.
- Resident 1. "The water came up over the curb in about ten minutes. It went down almost as fast once the rain stopped."
- Resident 2. "Those grates have been covered with leaves since the fall. I called about them in March."
- Resident 3. "It has flooded here twice before, and both times it was a hard, short storm rather than a long, steady one."
Directions. Work across one row at a time. Write "not addressed" in any cell a source does not speak to, because an empty cell and a silent source are different findings.
| Sub-question | Source A says | Source B says | Source C says | What the row supports, in one sentence |
|---|---|---|---|---|
| 1. How hard did it rain, and for how long? | (write here) | (write here) | (write here) | (write here) |
| 2. Was the rain heavier than the pipe was built for? | (write here) | (write here) | (write here) | (write here) |
| 3. Did blocked inlets matter? | (write here) | (write here) | (write here) | (write here) |
| 4. Why did Weald Street stay dry? | (write here) | (write here) | (write here) | (write here) |
| 5. Where does the runoff end up? | (write here) | (write here) | (write here) | (write here) |
Narrowing step. Name the one sub-question these three sources cannot settle, and write the single source you would need in order to settle it.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Completed Exemplar
| Sub-question | Source A says | Source B says | Source C says | What the row supports, in one sentence |
|---|---|---|---|---|
| 1. How hard did it rain, and for how long? | About 2.8 inches fell in the hour after 8:00 p.m., and 2.26 inches of that arrived in the half hour from 8:15 to 8:45. | Not addressed. | Resident 1 reports water over the curb within about ten minutes and gone almost as fast. | The storm was short and intense rather than long and steady, and the flooding tracked the burst rather than the total. |
| 2. Was the rain heavier than the pipe was built for? | The heaviest 15 minutes delivered 1.32 inches. | The line was designed for a storm dropping about one inch in an hour. | Resident 3 recalls that both earlier floods followed hard, short storms. | The gauge and the design standard together support the claim that the storm exceeded the pipe's design, and Resident 3's memory is consistent with that pattern rather than proof of it. |
| 3. Did blocked inlets matter? | Not addressed. | Two of four inlets were packed with leaf litter the next morning. | Resident 2 says the grates had been covered since fall and that a call was made in March. | Half the inlet capacity was unavailable, which would have made the flooding worse, though nothing here separates the share caused by leaves from the share caused by rainfall the pipe could not carry anyway. |
| 4. Why did Weald Street stay dry? | Not addressed. | Weald Street sits about six feet higher and drains to a grassed swale rather than a piped inlet. | Not addressed. | Elevation and a different drainage path explain the contrast, and only Source B speaks to it, so the claim rests on a single source. |
| 5. Where does the runoff end up? | Not addressed. | The line discharges to Skelmere Brook with no treatment. | Not addressed. | Whatever washed off Drayhollow Row reached the brook directly, which matters for any argument about street sweeping or leaf collection. |
Narrowing step, completed. Row 3 is the sub-question these sources cannot settle. Deciding how much of the flooding the leaves caused would require a hydraulic model of the block, or a record of a comparable storm on a night when the inlets were clear.
Model synthesis sentence. A storm that delivered more than two inches in half an hour overran a sewer built for about one inch in an hour, and two blocked inlets removed capacity the block was already short of, so the leaves made a flood worse without being its cause.
Differentiation
Support
Complete row 1 with the class and leave rows 2 through 5 to students. Provide the phrase "not addressed" as a printed sticker or a check box so that recording a silent source takes no writing. Give these students three of the five sub-questions rather than all five, keeping rows 1, 2, and 3, which are the rows the final sentence depends on.
Extension
Ask students to add a fourth source column for a document they specify themselves, such as a repair log or a rainfall record from a nearby town, and to write two sentences on which row that source would change and which rows it would leave exactly as they are.
ELL supports
Pre-teach "inlet," "swale," "intensity," and "corroborate" with a labeled street cross-section sketch showing a curb, a grate, and the pipe below it. Allow the source cells to be completed in phrases rather than sentences, and require full sentences only in the final column. Provide the frame "Sources A and B agree that ____, but only ____ speaks to ____" for the final column.
Extensions
Have students turn the completed matrix into a 250-word letter to the Ledstow public works director that states one recommendation and names the evidence behind it. Then ask them to mark every sentence in the letter with the row it came from, and to strike any sentence they cannot trace to a row, which is a quick test of whether the letter is carrying claims the sources never supported.