Worksheet Grade 11 Health & Consumer Science

The Delgado Household Water-Use Audit: Gallons and Savings

A grade 11 consumer-science worksheet where students audit a fictional household's daily water use by fixture and calculate the savings from WaterSense fixtures.

Grade: Grade 11
Subject: Health & Consumer Science
Material: Worksheet
Time: 40 min
Prep: No prep
Materials: Calculator

Standards

HSN-Q.A.1 Common Core Math

Use units as a way to understand problems and to guide the solution of multi-step problems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.

How this material aligns: Students carry units through the audit, moving from gallons per minute to gallons per shower to gallons per day and per month, the consistent-units reasoning this standard names.

All materials for HSN-Q.A.1 →

HSA-CED.A.1 Common Core Math

Create equations and inequalities in one variable and use them to solve problems. Include equations arising from linear and quadratic functions, and simple rational and exponential functions.

How this material aligns: Item 8 asks students to write and solve a one-variable inequality that keeps the household's daily shower use at or below a stated gallon limit, exactly the modeling this standard requires.

All materials for HSA-CED.A.1 →

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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 calculate a household's daily water use by fixture from flow rates and durations.
Students will compare standard and WaterSense fixtures to quantify water saved.
Students will write and solve an inequality that keeps daily shower use within a target.

Vocabulary

Flow rate: Flow rate measures how much water moves past a point in a certain amount of time, like gallons per minute through a garden hose. Bigger pipes and stronger pushes give bigger flow rates.
WaterSense: An EPA label on toilets, showerheads, faucets, and irrigation controllers that meet water-saving standards. It works like the ENERGY STAR label, but for water.
Water audit: A careful check of where water goes, either in a home or across a whole water system. Audits find leaks and waste so they can be fixed.

Also: gallons per minute

Teacher overview

A home water audit turns a monthly bill into a set of decisions a household can act on. In this worksheet students audit the fictional Delgado family of four in the fictional town of Cedar Junction, working from measured flow rates and daily habits. Students compare standard fixtures with WaterSense-labeled ones, and they close by writing an inequality that keeps the family's shower use within a target. A standard showerhead flows at 2.5 gallons per minute, while WaterSense models flow at 2.0 gallons per minute or less.

The Delgado Household Water-Use Audit: Gallons and Savings — Grade 11 Health & Consumer Science

Name: ____________________________ Date: ______________

Student Worksheet

The fictional Delgado household has four people. A standard showerhead flows at 2.5 gallons per minute (gpm); a WaterSense-labeled model flows at 2.0 gallons per minute or less. The average US household uses about 300 gallons of water per day, roughly 70% of it indoors.

Each of the four family members takes one 8-minute shower per day using a standard showerhead at 2.5 gallons per minute. How many gallons does one shower use, and how many gallons do all four showers use in a day?
The family replaces the standard showerheads with WaterSense models at 2.0 gallons per minute. With the same 8-minute showers, how many gallons would all four daily showers use?
How many gallons per day would the household save on showers by switching to the WaterSense showerheads?
Over a 30-day month, how many gallons would that shower change save?
On the day the Delgado family logged their use, the household used 348 gallons. The average US household uses about 300 gallons per day. By how many gallons did their use exceed the average, and what percent of the 300-gallon average is their 348-gallon use? Round to the nearest whole percent.
Roughly 70% of household water use is indoors. If the Delgado family's 348 gallons follows that split, how many gallons are used indoors and how many outdoors?
A slow faucet drip in the Delgado kitchen wastes about 3,000 gallons per year. If the family fixes it, how many gallons per year do they stop wasting, and about how many gallons per day is that? Round the per-day figure to the nearest whole gallon.
Write an inequality using s for the number of gallons the family uses on showers in one day that keeps their shower use at or below 60 gallons. Using the 2.0 gallons per minute WaterSense showerheads and four equal-length showers, what is the greatest whole number of minutes each person could shower and still meet that limit?
Explain in two or three sentences why replacing a showerhead reduces water use even when the length of the shower does not change.
The family can fix the dripping faucet (saving about 3,000 gallons per year) or shorten each shower by 2 minutes (four people, WaterSense showerheads at 2.0 gallons per minute). Which change saves more water in a year, and by about how many gallons?

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: 20 gallons per shower; 80 gallons for four. One shower is 2.5 gallons per minute times 8 minutes, which is 20 gallons; four showers are 20 times 4, or 80 gallons.
Answer: 64 gallons. Each WaterSense shower is 2.0 times 8, or 16 gallons; four showers are 16 times 4, or 64 gallons.
Answer: 16 gallons per day. The standard showers use 80 gallons and the WaterSense showers use 64 gallons, so 80 minus 64 is 16 gallons saved each day.
Answer: 480 gallons. Saving 16 gallons per day for 30 days gives 16 times 30, or 480 gallons.
Answer: 48 gallons over; 116%. The household used 348 minus 300, or 48 gallons above average; 348 divided by 300 is 1.16, or 116% of the average.
Answer: 243.6 gallons indoors; 104.4 gallons outdoors. Indoors is 0.70 times 348, which is 243.6 gallons; the rest, 348 minus 243.6, is 104.4 gallons outdoors.
Answer: 3,000 gallons per year, about 8 gallons per day. Fixing the drip stops 3,000 gallons per year; 3,000 divided by 365 is about 8 gallons per day.
Answer: 7 minutes. The inequality is s ≤ 60, and shower use is 4 times 2.0 times m, or 8m gallons; 8m ≤ 60 gives m ≤ 7.5, so the greatest whole number is 7 minutes.
Answer: Because the flow rate sets how many gallons leave the showerhead each minute. A lower flow rate delivers fewer gallons per minute, so a shower of the same length uses less water overall.
Answer: Shorter showers save more, by about 2,840 gallons per year. Shortening each shower by 2 minutes saves 2.0 times 2, or 4 gallons per person per day; for four people that is 16 gallons per day, or about 5,840 gallons per year, which is 5,840 minus 3,000, or about 2,840 gallons more than fixing the drip.

Differentiation

Support

Provide a worked example of a fixture calculation (flow rate times minutes) using a different showerhead before students begin, and give item 1 with the multiplication already set up as 2.5 times 8. Allow a calculator throughout and accept unrounded answers on items 5 and 7.

Extension

Ask students to build a one-day water budget for the Delgado household that keeps total use at or below 300 gallons, listing gallons for showers, an estimated indoor share, and outdoor use, and to justify each figure with the flow rates and habits given.

ELL supports

Pre-teach "flow rate," "fixture," "audit," and "WaterSense" with a simple labeled sketch of a showerhead and a faucet showing gallons per minute. Provide sentence frames for items 9 and 10, such as "The change that saves more water is ___ because ___."