Classroom activity Grade 2 Engineering & Design

Rainy Day at the Model House: A Grade 2 Rain Diverter Design Activity

Grade 2 teams define why water pools at a model house's door, then design, build, and test two foil or index-card diverters to route rain to a rain garden cup.

Grade: Grade 2
Subject: Engineering & Design
Material: Classroom activity
Time: 45 min
Prep: Moderate prep
Materials: Small toy house or wooden block per team (1), Plastic tray or bin per team (1), Small cups of water labeled 'rain' (3 per team, refilled for each test), Large cup labeled 'rain garden' per team (1), Aluminum foil strips (2 per team), Index cards (2 per team), Tape, Paper towels

Standards

K-2-ETS1-1 NGSS

Ask questions, make observations, and gather information about a situation people want to change to define a simple problem that can be solved through the development of a new or improved object or tool.

How this material aligns: Step 2 has teams ask questions and gather observations about why water pools by the model house's door, defining the simple problem the design must solve.

All materials for K-2-ETS1-1 →

K-2-ETS1-2 NGSS

Develop a simple sketch, drawing, or physical model to illustrate how the shape of an object helps it function as needed to solve a given problem.

How this material aligns: Step 4 has teams sketch and build a folded diverter shape, then explain how that shape carries water to the rain garden cup instead of the door.

All materials for K-2-ETS1-2 →

K-2-ETS1-3 NGSS

Analyze data from tests of two objects designed to solve the same problem to compare the strengths and weaknesses of how each performs.

How this material aligns: Step 6 has teams compare their first and second diverter designs using the number of cups of rain each one redirected before the model house door got wet.

All materials for K-2-ETS1-3 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-15.

Objectives

Students will define the problem of water pooling at a model house's door by asking questions and making observations.
Students will build a physical model of a diverter and explain how its shape solves the problem.
Students will compare test results from two different diverter designs.

Vocabulary

Stormwater: Stormwater is rain or melted snow that flows off roofs, streets, and parking lots. In most towns it goes into storm drains and flows to a stream without being treated, carrying whatever it picked up.

Teacher overview

This is a small-team design challenge for groups of three or four. Each team gets a toy house sitting in a tray, and pouring a cup of "rain" next to it floods the "yard" right up to the door, the same problem a real downspout or storm drain is built to solve. Teams design and test a diverter, a small folded piece of foil or an index card, that carries the water away from the door and into a "rain garden" cup instead, then compare two different diverter shapes to see which one works better.

Activity Directions

Split the class into teams of three or four. Give each team a tray with the model house placed in the middle and the "rain garden" cup set off to one side, outside the tray.
Pour one cup of "rain" next to the house, close to the door, without any diverter in place. Ask each team to observe and describe in their own words why the water is a problem for the house.
Explain the challenge: build a diverter that carries the rain away from the door and into the rain garden cup, using only foil, index cards, and tape.
Give teams 15 minutes to design and build their first diverter. Teams should sketch their idea first, then build it, and explain to a teammate how the shape of their diverter will carry the water toward the rain garden cup.
Test the first design: empty and dry the tray, then pour one cup of "rain" at a time next to the house in the same spot as before. Count how many cups of rain the diverter successfully carries to the rain garden cup before any water reaches the door, up to a maximum of three cups.
Teams build a second diverter with a different shape and repeat the test, again counting how many cups it redirects before water reaches the door. Teams compare their two designs and decide which one performed better.
End the activity when every team has tested both designs and recorded their two counts. Gather the class for a debrief.
Debrief: ask two or three teams to share which of their two designs worked better and what was different about its shape.

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

Answer Key

Debrief question: "Why did water pool by the house's door before any diverter was added?" Answer: The rain had nowhere else to go, so it spread across the flat tray and reached the door; a real yard without a gutter or drain has the same problem.
Debrief question: "What made one diverter design work better than the other?" Answer: Answers will vary by team, but strong answers point to a shape that fully blocked water from flowing toward the door, such as a diverter with raised edges or one placed directly in the water's path, and connect that shape to why it carried more cups of rain successfully.
Debrief question: "How does this activity connect to how real neighborhoods handle rain?" Answer: Real neighborhoods use gutters, downspouts, and storm drains, maintained by workers such as stormwater technicians, to carry rain away from buildings and streets in the same way the team's diverter carried water away from the model house.

Differentiation

Support (below grade level)

Provide one pre-built example diverter for teams to examine and describe before they design their own, and reduce the challenge to one design and one test instead of two, focusing the debrief on describing how the example worked.

Extension (above grade level)

Challenge teams to build a third diverter that redirects all three test cups without any water reaching the door, and have them write two sentences explaining which feature of their winning design mattered most.

ELL supports

Model the full test cycle once as a class demonstration before teams begin, narrating each step aloud with the matching action. Provide picture cards for "rain," "diverter," and "rain garden," and allow teams to report their cup counts by holding up fingers instead of speaking a full sentence.