WaterSense showerhead savings: 6 EPA figures to compare

Key takeaways

• Separate national totals from possible household savings.
• Keep gallons, kilowatt-hours and dollars separate.
• Read “could” as a possibility, not a promise.
• Use your own measurements for a household estimate.

Those figures are useful, but they do not all measure the same thing. Some describe the water all showers use across the country. Some describe what could be saved if every home made a change. One describes electricity, and one describes when the showerhead specification changed. Read side by side without context, they can sound like one large promise. They are not one promise.

This post takes six EPA figures one at a time. For each, it explains the scope, units and conditions. Every number and date in those figures comes from the EPA statements quoted here, and each one links to its source.

The aim is not to make a showerhead look better or worse. It is to help you read the numbers accurately. Use the post to compare the figures on their own terms before you decide anything about your own bathroom.

Figure 1: Showers use nearly 1.2 trillion gallons a year

EPA states that nearly 1.2 trillion gallons of water are used in the United States annually just for showering. The agency puts that in local terms: it is enough to supply the water needs of New York and New Jersey for a year. ( EPA, Showerheads)

This figure is a total, not a saving. It describes how much water showering uses across the country in a year. It does not describe one showerhead, one bathroom, or one household. The word "just" in EPA's sentence limits the figure to showering, so it does not cover the other ways water is used in a home.

Totals like this are hard to picture, which is why EPA's comparison helps. Even so, a national total should not be read as a household number. It gives a sense of scale, and nothing more.

The figure also covers a whole year. An annual total says nothing about a single week, and it does not separate one shower from the next. When you move from the national picture to your own bathroom, both the time period and the unit have to change with you.

When you see a large number like this in an advertisement or an article, ask one question first: is the number a total, or is it a saving? Those are different claims, and the rest of this post depends on keeping them apart.

Figure 2: The average family could save more than 330 kilowatt hours a year

EPA states that the average family could save more than 330 kilowatt hours of electricity annually. ( EPA, Showerheads) The word "could" matters. The statement describes a possible saving for an average family. It does not promise that your family will reach that number.

This figure differs from the water figures in two ways. First, it is electricity, measured in kilowatt-hours, not gallons or dollars. A kilowatt-hour is a unit of electrical energy, so do not add this figure to the gallon or dollar figures. Second, it describes an average family, not your family. An average is a single summary, so check whether your household is comparable.

For a personal estimate, record how many showers your family takes, how its water is heated, and which showerhead you are comparing. Those inputs would shape any estimate built on the figure, so they matter when you try to apply it to your own home.

If you want to test this figure against your own situation, you will need to set those inputs yourself. Label the result as your own estimate, not as EPA's. A simple method for doing that appears later in this post.

Think of the figure as a starting point for a question, not as an answer. The question is what your own family's showers, water heating and electricity costs would produce. Only your own records can answer that question.

Figure 3: A house's power for 11 days illustrates the electricity saving

EPA describes the saving of more than 330 kilowatt hours as "enough to power a house for 11 days." ( EPA, Showerheads) This comparison helps you picture the more-than-330-kilowatt-hour figure. It is not a separate saving, and it should not be added to Figure 2.

Read the 11 days with the same care as the electricity figure. The statement names "a house" without describing it. A comparison with your home would need its size, heating method and power use. The 11 days therefore cannot be applied directly to your home. Treat it as an illustration of scale, not as a measured result for your house.

One common mistake is to read "11 days" as 11 days of shower time or 11 days of water. The statement is about power. Keep the unit straight: the 11 days refers to electricity, and it illustrates the possible saving of more than 330 kilowatt hours described in Figure 2.

Figure 4: More than $2.9 billion in water utility bills, nationally

EPA states that if every home in the United States installed WaterSense labeled showerheads, "we could save more than $2.9 billion in water utility bills and more than 260 billion gallons of water annually." ( EPA, Showerheads)

This is a national scenario, and its condition appears in the first clause: every home in the United States installing WaterSense labeled showerheads. Treat that condition as a scenario rather than a timetable or forecast.

The dollar figure is stated in water utility bills. It is therefore a water-bill figure, not a total of all household costs. It is also not a bill estimate for any single household, including yours. The statement is framed on a national scale.

Pay attention to the verb. EPA says "could save," which describes a possibility under a stated condition. Restating this as "Americans will save $2.9 billion" would make a stronger claim than the source makes, and that stronger version is not supported by the statement.

Because the scenario is national, its dollar figure cannot be checked against a single water bill. To test the idea against your own bill, you would need household inputs, such as how much water your household uses and what it pays for that water.

Figure 5: More than 260 billion gallons of water a year

The same sentence gives the water side of the national scenario: more than 260 billion gallons of water annually. ( EPA, Showerheads)

This is the water counterpart to Figure 4. It is an annual figure, and it depends on the same condition: every home in the United States installing WaterSense labeled showerheads.

It is natural to compare this figure with Figure 1. Both are national and annual, so they share units. But they measure different things. Figure 1 is the total water used for showering. Figure 5 is the amount EPA says could be saved under the every-home scenario. Setting them side by side shows the scale of each. Keep the total and the conditional saving distinct when comparing them.

Avoid adding gallons from Figure 5 to Figure 1, and avoid combining gallons with kilowatt-hours or dollars. Each number answers a different question.

Figure 6: Version 1.1 replaced Version 1.0 of the showerhead specification

Version 1.1 of the WaterSense Specification for Showerheads replaces Version 1.0, which EPA released on March 4, 2010. ( EPA, Showerheads) EPA also says it released the revised version in July 2018. (EPA, Showerheads)

The revision also reflects changes elsewhere. EPA says "the changes also reflect recent revisions to the American Society of Mechanical Engineers (ASME) A112.18.1/Canadian Standards Association (CSA) B125.1 Plumbing Supply Fittings standard, which is now consistent with the WaterSense Specification for Showerheads." ( EPA, Showerheads) The changes reflect revisions to that standard; the standard is now consistent with the WaterSense specification.

The dates are not savings figures. They tell you which version of the specification a source may mean. If you see a reference to either version, the year helps you tell which one it is, and the statement is clear that Version 1.1 replaces Version 1.0. If a product listing or article refers to the WaterSense specification, check which version it means before you treat the reference as current. The version name and the date go together, so use both when you check.

Today, choose one showerhead claim and write down its scope, unit and conditions beside your current showerhead's measured flow.

Questions to ask before you buy

Does the national saving predict my household saving?

No, a national scenario is not a bill estimate for your household. Compare it with your own water use and charges instead.

Does “could” mean my household will save that amount?

No, “could” describes a possibility under the stated conditions. Check how those conditions compare with your showers and water heating.

Can I combine the water, electricity and dollar figures?

No, gallons, kilowatt-hours and dollars measure different things. Keep them separate when comparing claims.

What should I check about the specification?

Check which version the claim cites. Use the version name and release date together when reviewing a product listing or article.

What should I collect before estimating savings?

Collect your current showerhead's flow, usual shower length and water charges. For a wider purchase plan, see water saving home upgrades.

What a household estimate needs

A household estimate needs inputs that match your bathroom and bills. Collect the following before calculating:

• the showerhead being replaced
• how long each shower lasts, and how many showers a household takes
• how the household heats its water
• which water rates or electricity rates your calculation uses
• how many people live in the household, and how many bathrooms it has

These inputs help turn a broad comparison into a personal estimate. A figure without its inputs can tell you the scale of an idea, but it cannot tell you what your own bathroom will save.

The gap matters most for the electricity figures. Heating water takes energy, so check your household's water heating before estimating electricity savings. The water figures need household measurements too: record how much water your household's showers use.

When a source does give its assumptions, use them. When it does not, your comparison is only as good as the numbers you measure or collect yourself. That is a reasonable standard for any product decision, and it is the standard this post applies to the EPA statements.

Compare the figures by scope and units first

Compare each figure by what it measures and which units it uses before you put any two side by side. The steps below work through that comparison in order.

1. Check the scope. Is the figure a national total, a national scenario, an average family, or a single house? Figures 1, 4 and 5 describe the country as a whole. Figure 2 describes an average family. Figure 3 describes a house.

2. Check the unit. Gallons, kilowatt-hours and dollars answer different questions. Keep them in separate columns when you take notes.

3. Check the verb. "Could" describes a possibility. A statement that says "will" makes a stronger claim, and you should ask what supports it before you rely on it.

4. Check the version. If a source refers to the WaterSense specification, note which version it means, using the dates in Figure 6 as a reference point.

5. Check the label. EPA's statements refer to WaterSense labeled showerheads, so look for that label on any product you are considering. The label is the thing the national scenarios describe.

6. Read the factsheet. EPA's Showerheads page says a WaterSense Labeled Showerhead Factsheet is also available in PDF. The factsheet is one page. ( EPA, Showerheads)

7. Make your own estimate and label it. Replace the EPA averages with numbers from your own home, and note clearly that the result is yours.

Build your own estimate from your own inputs

You can estimate your own water savings by replacing EPA's averages with inputs from your own bathroom. The method below is a general approach for a household estimate, separate from EPA's figures.

Start with water. Gallons saved each year equals the difference in gallons a minute between your old showerhead and the new one, multiplied by the minutes in an average shower, multiplied by the number of showers each year. Each part should come from your own situation. If you can, measure the flow of your current showerhead with a bucket and a timer rather than guessing. Measure the new showerhead's flow in the same way if you can, so the two numbers come from the same method.

Next, convert gallons into dollars. Take the gallons saved and apply the rate on your own water bill. Water bills can use different rate structures, so use the rate that actually applies to your household. See how to read your water charges when checking the bill.

Electricity is harder to estimate, because it depends on how your water is heated. To compare your home with EPA's possible saving of more than 330 kilowatt hours, use your own heating information. If that information is unavailable to you, leave electricity out of your estimate and say so.

Once you have your numbers, write them down with their sources. A note that says "my bucket test" or "my water bill" is much more useful later than a bare figure. Keep a simple record as you go: the date, the number, and where it came from. A measured number is easier to defend than a guess, and it is easier to revisit when you learn more.

Illustrative example: Calculate water saved during a shower

This is a household calculation, not an EPA prediction. Use your own measured flow difference and shower length before extending the calculation across a year.

What to take away

Use the figures to understand scale. Use your own measurements to make the decision. Any estimate for your home needs your own inputs, and it should be labeled that way.