Writing prompt Grade 6 Health & Consumer Science
Why Sculley Creek Closes After a Storm in Larchgrove
A grade 6 informative writing prompt asking students to explain a fictional park's rain closure rule for a creek swim area using runoff data and test results.
Objectives
- Students will explain in writing how rain changes the water quality of a local creek.
- Students will define runoff and the closure rule in their own words for a family audience.
- Students will compare two test readings and state how many times higher one is than the other.
Vocabulary
- 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: runoff, bacteria, advisory
Teacher overview
Swim areas on creeks and rivers close after heavy rain because stormwater washes bacteria off streets, yards, and fields into the water, and a creek seen from the bank gives no sign of it. This prompt asks students to write the explanation the fictional Larchgrove parks department would mail to families, which gives sixth graders an authentic reason to define a term, order a set of steps, and close with a statement that follows from evidence. The misconception to address directly is the belief that clear water is clean water. Bacteria are far too small to see, so the readings in the table can rise sharply while the creek still looks the same from the footbridge.
Prompt
Background. Sculley Creek runs through Millbrace Park in the fictional town of Larchgrove. Families swim at a shallow bend below the footbridge all summer. When rain falls on the town, water runs off roofs, driveways, parking lots, and lawns instead of soaking into the ground. That moving water is called runoff, and it carries whatever it passes over into the storm drains, which empty straight into the creek without any treatment. Pet waste, goose droppings, and material washed off farm fields upstream all ride along with it. The parks department in this scenario closes the swim area for 48 hours whenever the town records 1 inch of rain or more in a day, then tests the water before reopening it.
Table 1. Rain and closures last summer
| Week beginning | Rain in the heaviest day (inches) | Swim area closed? |
|---|---|---|
| June 8 | 0.2 | No |
| June 22 | 1.4 | Yes |
| July 6 | 0.6 | No |
| July 20 | 2.1 | Yes |
| August 3 | 1.0 | Yes |
Table 2. Bacteria readings at the swim bend, in colonies per 100 milliliters
| When the sample was taken | Reading |
|---|---|
| Dry weather, five days after any rain | 40 |
| One day after the July 20 storm | 480 |
| Three days after the July 20 storm | 55 |
Your task. Write an explanatory article for the Larchgrove parks newsletter. Your readers are families who swim at the creek. Explain what runoff is, how it changes the creek after a storm, and why the swim area closes for two days. Use details from the background and from both tables. Include one sentence that says how many times higher the reading was one day after the July 20 storm than in dry weather. End with a paragraph that tells families what to watch for before they head to the creek.
Planning Organizer
Fill in every row before you start your draft.
| Part of my article | What I will write |
|---|---|
| Opening sentence that tells readers what this article explains | |
| My definition of runoff, in my own words | |
| What happens to the creek after a heavy rain (use Table 2) | |
| Why the closure lasts two days (use Table 2 and the background) | |
| Which rain amounts trigger a closure (use Table 1) | |
| My comparison sentence, with the times-higher number | |
| Closing paragraph telling families what to check |
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Exemplar & Rubric
Exemplar response
If you swim at the bend below the footbridge in Millbrace Park, you have probably seen the yellow sign that closes the creek after a storm. The creek usually looks the same on those days, so the sign can be confusing. This article explains what changes in Sculley Creek when it rains and why the parks department waits two days before letting anyone back in.
Runoff is rain that flows across the ground instead of soaking into it. When rain hits a roof, a driveway, or a parking lot, the water has nowhere to sink, so it runs downhill and into the storm drains. Those drains do not go to a treatment plant. They empty into Sculley Creek. Anything the water passed over on the way, including pet waste, goose droppings, and material washed off farm fields upstream, arrives in the creek with it.
The test results show what that does to the water. In dry weather, five days after any rain, the swim bend measured 40 colonies per 100 milliliters. One day after the storm on July 20, the same spot measured 480. That is 12 times higher than the dry-weather reading, because 480 divided by 40 equals 12. Bacteria are far too small to see, so the creek can look exactly the way it always does while the reading climbs.
The closure lasts two days because the creek cleans itself out over time. Three days after the July 20 storm, the reading had dropped back to 55, close to where it sits in dry weather. Moving water carries the runoff downstream, sunlight breaks down some of the bacteria, and the storm drains stop flowing once the rain ends. Waiting gives that process time to work. The parks department closes the swim area whenever the town records 1 inch of rain or more in a day, which last summer meant closures after the storms on June 22, July 20, and August 3, but not after the lighter rains on June 8 and July 6.
Before you head to the creek, check two things. Look up how much rain fell in the last two days, and look for the sign at the trailhead. If the town got an inch or more of rain yesterday, the bend will still be closed even if the water looks clear. Coming back on the third day is the safer plan.
Rubric
| Criterion | 1 Emerging | 2 Developing | 3 Proficient | 4 Advanced |
|---|---|---|---|---|
| Topic and definition | The article never says what it explains, or runoff is left undefined. | An opening appears, but the definition of runoff is copied word for word from the background. | The opening names the topic and runoff is defined clearly in the writer's own words. | The opening names the topic, and the definition is in the writer's own words with an example a family would recognize. |
| Use of the tables | Neither table is used. | One table is used, or numbers are copied incorrectly. | Both tables are used correctly, and the times-higher comparison is computed and stated. | Both tables are used, the comparison is correct, and the writer explains what the three-day reading shows about the creek recovering. |
| Organization and transitions | Ideas appear in no clear order. | Some order is visible, but paragraphs jump between ideas. | Paragraphs move in order from what runoff is, to what it does, to why the wait lasts two days, with transitions between them. | The order is clear and transitions connect each paragraph to the one before it without repeating the same connecting word. |
| Closing and conventions | No closing, and errors make sentences hard to follow. | A closing exists but does not tell families what to check, or errors slow the reader. | The closing tells families what to check before swimming, and errors are few. | The closing follows directly from the evidence given earlier, and conventions are clean throughout. |
Differentiation
Support
Give these students the opening sentence and the definition row of the organizer already filled in, so drafting starts from the tables. Provide the division for the comparison already set up as 480 over 40.
Extension
Ask students to add a short section explaining what the town could build or change so that less runoff reaches the creek, and to say which of their ideas would take the longest to finish.
ELL supports
Pre-teach "runoff," "storm drain," "bacteria," and "advisory" with a labeled diagram of rain hitting a street, entering a grate, and leaving a pipe at a creek bank. Provide sentence frames: "Runoff is ___." and "The reading after the storm was ___ times higher than the dry-weather reading."
Extensions
Have students walk the school grounds and map where rain would run off the pavement, then mark on their map the nearest storm drain and write one sentence predicting where that water goes.