Water for Schools
Menu

Reading passage Grade 6 English Language Arts

Cobblestone Creek: A Grade 6 Storm Drain Pollution Reading Passage

A grade 6 informational passage explaining how storm drains carry untreated runoff to a fictional creek, tracing one storm's fertilizer and litter pathway.

Objectives

  1. Students will identify how storm drains differ from the sanitary sewer system, based on details in the passage.
  2. Students will infer why an everyday choice can affect water quality in a nearby creek.

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.
Sanitary sewer
A sanitary sewer is an underground pipe that carries used water from buildings to the wastewater treatment plant. It is a separate system from the storm drains that carry rainwater.

Also: runoff, outfall, nutrient

Teacher overview

Cobblestone Creek runs behind a fictional neighborhood where storm drains carry rainwater directly from streets into the creek without any treatment. This passage explains what a storm drain actually does and follows one specific rainstorm to show how litter and yard chemicals can travel from a driveway to a creek in a matter of minutes. A common misconception this passage addresses is that storm drains connect to the same treatment plant as sinks and toilets; the passage states directly, and asks students to locate the sentence, that storm drains usually flow untreated straight to the nearest body of water.

Cobblestone Creek: A Grade 6 Storm Drain Pollution Reading Passage — Grade 6 English Language Arts
Name: ____________________________ Date: ______________

Passage

Underneath most streets, two separate systems carry water away. One system is called the sanitary sewer. It carries water from sinks, toilets, and showers to a treatment plant. There, the water is cleaned before it returns to a river. The other system is called the storm drain. It carries rainwater from streets, sidewalks, and roofs. Storm drains do not lead to a treatment plant. In most towns, whatever flows into a storm drain flows straight into the nearest creek, river, or lake. It reaches that water completely untreated.

Cobblestone Creek runs behind a fictional neighborhood. Every street there has metal grates set into the curb. These grates mark the openings of the storm drain system. On an ordinary dry day, the grates sit empty and mostly unnoticed. During a rainstorm, water rushes across driveways and sidewalks. It picks up whatever sits in its path. Then it disappears through the grates. Minutes later, that same water reappears in the creek.

One spring storm showed exactly how fast that path is. A resident on Birch Lane had left a bag of yard fertilizer open near the curb. Rain was expected that night. When the storm hit the next morning, runoff carried a visible trail of fertilizer granules down the gutter. The runoff carried the fertilizer straight through the nearest grate. A stormwater technician happened to be testing the creek that same morning. Within an hour of the storm's start, she found a cloudy patch of water near the outfall pipe. That is the point where the storm drain empties into the creek. Nutrients from fertilizer reached the creek almost as fast as the rain had fallen. This is much like the nutrients from lawns that can trigger algae growth in a lake.

Litter follows the same path as fertilizer. A plastic bottle left near a storm drain grate does not decompose before reaching the creek. It simply washes through the system and out the other end, sometimes within the same storm. Motor oil dripped in a driveway travels this same route. So does pet waste left on a sidewalk. So does soap from washing a car. Storm drains are built to move water quickly. They are not built to filter or treat anything that water happens to be carrying.

This is why many towns paint or stencil a message next to storm drain grates. A common message reads "No Dumping, Drains to Creek." Some towns use a small fish icon instead. The message reminds residents that whatever enters the grate has a direct, untreated path to the water. Fish and other animals live in that water. Cobblestone Creek's neighborhood association adopted a similar stencil program after the fertilizer incident. Each grate on Birch Lane now has a painted fish and the words "Flows to Creek." Residents who see the stencil while walking past are far more likely to clean up a spill or pick up litter before the next storm. That is what the technician who found the cloudy water later reported.

Understanding this system changes how a neighborhood thinks about ordinary tasks. Raking leaves into the street sends organic material straight toward the nearest storm drain. Those leaves can decompose in the creek. Decomposing leaves use up oxygen that fish need to survive. This is similar to the way nutrient runoff feeds an algae bloom. A single rainstorm can turn one small, ordinary choice on Birch Lane into a measurable change in the creek. That change can appear by the very next afternoon.

Questions

  1. According to the passage, what is the difference between the sanitary sewer system and the storm drain system?
  2. What happened on Birch Lane during the spring storm described in the passage?
  3. Quote the sentence that explains where water in a storm drain usually ends up.
  4. Why does litter reach a creek so quickly after entering a storm drain, according to the passage?
  5. Based on the passage, why might painting a fish stencil next to a storm drain grate change how residents behave?
  6. The passage compares fertilizer runoff to "the nutrients from lawns that can trigger algae growth in a lake." What is the passage suggesting by making this comparison?
  7. Why do you think raking leaves into the street could affect the oxygen fish need in Cobblestone Creek? Use details from the passage.
  8. What is one everyday choice mentioned in the passage that could send pollution toward the creek?

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: The sanitary sewer carries water from sinks, toilets, and showers to a treatment plant to be cleaned, while the storm drain carries rainwater from streets and roofs directly to a nearby creek, river, or lake without treatment.
  2. Answer: A resident left fertilizer near the curb, and rain carried it through a storm drain grate into Cobblestone Creek, where a technician found cloudy water near the outfall pipe within an hour.
  3. Answer: "In most towns, whatever flows into a storm drain flows straight into the nearest creek, river, or lake." (Also accept the next sentence, "It reaches that water completely untreated.")
  4. Answer: Storm drains are built to move water quickly rather than to filter or treat anything in it, so litter simply washes through the system with the rainwater instead of being caught or broken down.
  5. Answer: Answers will vary but should reference that a direct, visible reminder that the grate leads to the creek, rather than a treatment plant, makes residents more aware of the connection, which the passage suggests led people to clean up spills and litter before storms.
  6. Answer: The passage is suggesting that fertilizer runoff and lawn runoff cause the same kind of problem, adding nutrients to water that can lead to algae growth, connecting a small yard choice to a larger water-quality issue.
  7. Answer: Answers will vary but should reference that decomposing leaves use up oxygen in the water as they break down, similar to the way nutrient runoff feeds algae growth, and fish need enough oxygen in the water to survive.
  8. Answer: Any one of: leaving fertilizer near the curb, littering, letting motor oil drip in a driveway, leaving pet waste on a sidewalk, washing a car with soap in the driveway, or raking leaves into the street.

Differentiation

Support (below grade level)

Provide a simple two-column chart labeled "Sanitary Sewer" and "Storm Drain" with one detail already filled in on each side, and have students complete the chart using the passage before answering item 1.

Extension (above grade level)

Ask students to design their own storm drain stencil message, different from "Flows to Creek," and write two sentences explaining, using evidence from the passage, why their chosen wording would change a resident's behavior.

ELL supports

Provide a simple diagram showing two pipes leaving a house, one labeled "to treatment plant" and one labeled "to creek," before reading, and allow students to answer items 1, 2, and 3 with short phrases or by pointing to the diagram instead of writing full sentences.