Quiz & test questions Grade 8 Engineering & Design

Culverton's Flooded Underpass: A Stormwater Design Assessment

A grade 8 assessment mixing multiple-choice, computation, and design short-answer items on reducing runoff, using the rational method and scientific notation.

Grade: Grade 8
Subject: Engineering & Design
Material: Quiz & test questions
Time: 30 min
Prep: No prep
Materials: Calculator

Standards

8.EE.A.3 Common Core Math

Use numbers expressed in the form of a single digit times an integer power of 10 to estimate very large or very small quantities, and to express how many times as much one is than the other.

How this material aligns: Item 7 has students write a large national infrastructure dollar figure in scientific notation, the estimate-and-express-with-powers-of-ten skill this standard names.

All materials for 8.EE.A.3 →

MS-ETS1-1 NGSS

Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.

How this material aligns: Items 1 through 5 frame the flooded underpass as a runoff problem with a measurable target for reducing peak flow, defining criteria and constraints as this standard requires.

All materials for MS-ETS1-1 →

MS-ETS1-3 NGSS

Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.

How this material aligns: Item 8 has students use test results from the built change to decide the next redesign step, the analyze-and-iterate work this standard describes.

All materials for MS-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 2026-07-23.

Objectives

Students will compute peak runoff before and after a design change using the rational method.
Students will express a large infrastructure figure in scientific notation and reason through a design iteration.

Vocabulary

Green infrastructure: Green infrastructure uses soil and plants, like rain gardens, green roofs, and street trees, to soak up rainwater where it falls instead of piping it away. It copies the way nature handles rain.

Also: runoff coefficient, rational method, scientific notation

Teacher overview

This 30-minute assessment is worth 24 points and checks whether students can size stormwater runoff and reason through an engineering redesign. It mixes two multiple-choice items, three computation items, one scientific-notation item, and two short-answer design items. The runoff math uses the rational method, Q = C x i x A, where C is the runoff coefficient, i is the rainfall intensity, and A is the drainage area.

Culverton's Flooded Underpass: A Stormwater Design Assessment — Grade 8 Engineering & Design

Name: ____________________________ Date: ______________

Assessment

Suppose the town of Culverton, a fictional town, has an underpass that floods in storms because a paved parking lot upstream sends fast runoff toward it. Engineers want to lower the peak runoff.

(2 points) In the rational method Q = C x i x A, what does C stand for?
- A) pipe cost
- B) runoff coefficient
- C) channel slope
- D) chlorine dose
(2 points) Which surface usually has the higher runoff coefficient?
- A) a grassy lawn
- B) a paved parking lot
(4 points) The parking lot has an area of 3 acres, the rainfall intensity is 2 inches per hour, and the runoff coefficient is 0.9. Find the peak runoff Q in cfs using Q = C x i x A.
(4 points) The redesign lowers the effective runoff coefficient to 0.5, with the same 2 inches per hour and 3 acres. Find the new peak runoff Q in cfs.
(4 points) By what percent does the peak runoff drop from item 3 to item 4? Round to the nearest whole percent.
(3 points) Name one green-infrastructure change that lowers a parking lot's runoff coefficient, and explain in one sentence why it helps.
(2 points) EPA estimates the country needs $625 billion in drinking-water infrastructure over 20 years. Write $625 billion in scientific notation.
(3 points) After the change is built, the underpass still floods a little in the biggest storms. Using the engineering design process, describe what the team should do next.

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

Answer Key

Answer: B) runoff coefficient.
In the rational method, C is the runoff coefficient, a number that describes how much rain runs off a surface instead of soaking in.
Answer: B) a paved parking lot.
A paved lot sheds almost all rain, so its coefficient is near 0.9, while a grassy lawn lets water soak in and sits near 0.2.
Answer: 5.4 cfs.
Q = C x i x A = 0.9 x 2 x 3 = 5.4 cfs.
Answer: 3.0 cfs.
Q = 0.5 x 2 x 3 = 3.0 cfs with the lower runoff coefficient.
Answer: 44%.
The drop is 5.4 minus 3.0 = 2.4 cfs. Then 2.4 divided by 5.4 = 0.444, which rounds to about 44 percent.
Answer: Permeable pavement (or a rain garden, or added trees).
Any change that lets water soak into the ground instead of running off lowers the coefficient. For example, permeable pavement has gaps that let rain pass through into the soil, so less water rushes to the underpass.
Answer: 6.25 x 10^11.
625 billion is 625,000,000,000, which is 6.25 x 10 to the 11th power.
Answer: Test, find the weak point, and redesign.
The team should collect data on where and when it still floods, use that to find what the design missed, change the design to add capacity, and then test again. This is the test-and-improve loop of the engineering design process.

Differentiation

Support

Provide the rational-method formula with each letter labeled and the values for items 3 and 4 already placed in the formula, so students focus on the arithmetic. Allow a calculator and give the percent-change setup (difference divided by the original) for item 5.

Extension

Ask students to find what runoff coefficient the redesign would need to cut the peak runoff in half from the item 3 value, and to name a mix of surfaces that could reach it.

ELL supports

Pre-teach runoff coefficient with a simple picture of rain hitting pavement versus grass, and label which soaks in. Provide a sentence frame for item 6: "A ___ helps because it lets water ___ instead of running off."