How to Read Your Water Bill: CCF, Tiers and Sewer

What is on the bill

Layouts differ from utility to utility, but almost every residential water bill has the same building blocks. Find these before you look at the total:

Billing period. The start and end dates, or the number of days. Some utilities bill monthly, others every two or three months. A longer period means more water and often a larger fixed charge.
Meter readings. The previous and the current reading. Your usage is the current reading minus the previous one.
Usage. The difference, in the unit your meter counts: CCF (also written HCF), cubic feet or gallons.
Charges. The EPA's WaterSense program says many utilities combine a fixed base fee with a variable volume charge. Your bill's "billing detail" or "summary of charges" should list them, and surcharges are usually explained on the back of the bill or on the utility's website.
Sewer and other services. Many bills also carry sewer charges, and some add stormwater, as Portland's does.

Some bills add a graph of your use over the past year. The EPA points out that use is usually higher in summer, and that a rise without more outdoor watering may signal a leak. That graph is the quickest health check on the whole page.

Units: CCF, HCF, cubic feet and gallons

The EPA names the two most common billing units: the CCF and the gallon. CCF means 100 cubic feet. The EPA explains that the C comes from the Latin word for hundred. It is not the metric prefix centi, which means a hundredth. HCF, "hundred cubic feet", is the same unit. Portland, Oregon puts it plainly on its rate page: one ccf is 748 gallons.

Where the 748 comes from: a US gallon is exactly 231 cubic inches (NIST Handbook 44) and a cubic foot is 1,728 cubic inches, so a cubic foot holds 7.48052 gallons. The NIST SI guide's own factors give the same result: 2.831685 × 10⁻² m³ per cubic foot divided by 3.785412 × 10⁻³ m³ per gallon is 7.48052. The pool volume calculator shows the derivation step by step. Times 100:

1 CCF in gallons

100 × 7.48052 = 748.05 gal

1,000 gallons in CCF

1,000 ÷ 748.05 = 1.3368 CCF

Utilities that bill in gallons usually price per 1,000 gallons; Denver Water, for example, lists its volume rates in dollars per 1,000 gallons. If a bill shows kgal, the k is the SI prefix kilo, which NIST defines as a thousand. So 1 kgal is 1,000 gallons, not 1,000 cubic feet.

CCF (HCF)	Cubic feet	US gallons	Thousand gallons
1	100	748	0.75
5	500	3,740	3.74
10	1,000	7,481	7.48
15	1,500	11,221	11.22
20	2,000	14,961	14.96

The same factor converts prices. A price per CCF divided by 0.748 is the price per 1,000 gallons; a price per 1,000 gallons times 0.748 is the price per CCF. Portland's 2026-27 water rate of $8.83 per ccf is $11.81 per 1,000 gallons. Denver's 2026 first-tier rate of $3.02 per 1,000 gallons is $2.26 per CCF. That only puts two rates in one unit. It says nothing about which city's water is cheaper overall, because fixed charges, tiers and sewer differ completely. For any other volume unit, such as liters or cubic meters, use the volume converter.

Fixed charges and volume charges

The EPA splits a water bill into two kinds of charges:

Fixed charges (often called a base, service, meter or customer charge). In the EPA's words, they generally include "the price the customer pays as a base charge". They help pay for maintaining existing infrastructure and for repaying the loans and bonds used to build it. You pay them whether you use one gallon or ten thousand.
Variable charges, "the price the customer pays per volume of water used". They cover costs such as treating the water and the energy to pump and deliver it.

The difference matters as soon as you try to save. Saving water only reduces the variable part. In the EPA's own sample bill on a uniform rate, roughly half of the $147.62 total was directly related to water use, so even a large cut in use cannot halve that bill.

Fixed charges are not always a flat monthly amount. Portland charges its 2026-27 base charge per day: $0.89 a day on quarterly bills, which the city sums up as "about $80.15 per bill, depending on how long the billing period is". $0.89 × 90 days = $80.15. A longer period between readings raises the fixed part too. Denver Water, by contrast, lists a fixed charge per bill: $20.91 for the common small meter sizes inside the city in 2026.

The same logic applies to the other utility bills. The gas bill guide and the electric bill guide split their bills into fixed and per-unit parts in the same way.

Tiered rates and other rate structures

How the volume charge is priced depends on the rate structure. The EPA lists these:

Flat fee. Everyone pays the same, whatever they use. The EPA says this is rarely used today.
Uniform rate. One price per unit for all water, all year.
Increasing block rate (tiers). Each block of use costs more per unit than the one before. The EPA says this is common in urban areas and where supply is limited.
Declining block rate. Each further block costs less per unit, more common in rural farming areas, areas with heavy industry and places where water is plentiful.
Seasonal and drought rates. Higher prices in summer or during declared drought levels.
Water budget rate. Each household gets a budget based on the number of residents or the property size; use above it costs more.

With tiers, the rate applies only to the water inside each block, the way tax brackets work. Your first units are always billed at the first-tier rate, even in a month when you reach the top tier.

Some utilities set the tiers per customer. Denver Water's 2026 tier 1 runs from zero to your average winter consumption (AWC), "calculated by averaging each customer's billed monthly water use from January through March", with a minimum of 5,000 and a maximum of 15,000 gallons. Tier 2 covers the next 15,000 gallons above that, and tier 3 everything beyond.

The practical point: the price of your next unit of water is the rate of the tier you are in, not the average price on the bill. That marginal rate is what a leak, a garden or a pool really costs you.

Sewer charges: often billed on your water use

Wastewater leaving a house is rarely metered. The EPA explains that some utilities meter both the incoming water and the outgoing sewer flow, but "many utilities have only one meter on location and will charge both volumes based on water entering the house." Sewer is then a second volume charge on the same CCF.

Water used outdoors does not reach the sewer, so many utilities limit the sewer volume. Portland is one example. The Portland Water Bureau says single-family homes have no sewer meter, so the city estimates sewer use from winter water use, when most water is used indoors. It bills sewer "using your winter average or your actual water use, whichever is lower". The winter average comes from the quarterly reading taken between February 1 and April 30, and it sets the sewer volume for the next three quarterly reads.

Two consequences follow, at least where a winter average is used:

Summer watering is cheaper than it looks. Once you are above your winter average, an extra unit costs only the water rate, not water plus sewer.
A winter leak costs you all year. Portland warns that leaks during the winter period raise the winter average and with it the sewer charges for the rest of the year. Fix leaks before the averaging months.

Sewer rates can be the larger half. Portland's 2026-27 residential sewer rate is $14.24 per ccf against $8.83 for water. Both went up on July 1, 2026: water by 8.1% from $8.17 and sewer by 5.2% from $13.54. Rules differ between utilities, so check your own utility's rate page for the method that applies to you.

A worked bill, line by line

Here is a full bill with made-up example rates, chosen only to show how the parts fit together. They are not any utility's prices; use the figures from your own bill.

Billing period: 30 days. Meter readings in CCF: previous 2,318, current 2,332.
Water service charge $15.00, sewer service charge $12.00, both fixed.
Water tiers: first 5 CCF at $4.00, the next 10 CCF at $5.50, everything above 15 CCF at $7.50.
Sewer: $6.00 per CCF on the lower of actual use or a winter average of 8 CCF.

Usage is 2,332 − 2,318 = 14 CCF, or 10,473 gallons.

Line	Quantity	Rate	Amount
Water service charge	1 bill	fixed	$15.00
Water, tier 1 (0 to 5 CCF)	5 CCF	$4.00	$20.00
Water, tier 2 (5 to 15 CCF)	9 CCF	$5.50	$49.50
Water, tier 3 (over 15 CCF)	0 CCF	$7.50	$0.00
Sewer service charge	1 bill	fixed	$12.00
Sewer volume (winter average)	8 CCF	$6.00	$48.00
Total			$144.50

What the example shows:

The fixed part is $27.00, or 19% of the bill. No saving touches it.
The all-in average is $144.50 ÷ 10.47 thousand gallons = $13.80 per 1,000 gallons.
The marginal price is lower. One more CCF lands in tier 2 at $5.50, and sewer does not change because use is already above the winter average. That is $7.35 per 1,000 gallons, or 0.74 cents a gallon.
In a month when sewer follows actual use, each extra CCF costs water plus sewer: $5.50 + $6.00 = $11.50.

The marginal price is the one to use for one-off decisions. Filling a 15,000-gallon pool, for example, takes 20.1 CCF. On top of the example month's 14 CCF, one CCF still falls in tier 2 and the rest in the top tier at $7.50, so the pool adds $148.39 to the bill, plus sewer if you fill it during the averaging months. The pool volume calculator gives the gallons for your pool.

How much water is normal

To judge your usage line, compare it with the EPA's WaterSense figures. They are national averages, and the EPA notes that use varies by region, mostly with the weather:

"Each American uses an average of 82 gallons of water a day at home."
"The average American family uses more than 300 gallons of water per day at home." Roughly 70 percent of that is indoors.
A family of four uses around 10,000 gallons in a 30-day period.
Outdoor use is more than 30 percent of household use on average, and can reach 60 percent in arid regions.

Converted to the unit on most bills:

Household	Gallons	CCF
One person, 30 days (82 gallons a day)	2,460	3.3
Family, 30 days at 300 gallons a day (EPA: more than 300)	9,000	12.0
Family of four, 30 days (EPA estimate)	10,000	13.4
Family of four in a winter month: EPA leak warning above	12,000	16.0

If your bill covers two or three months, divide the usage by the number of days and multiply by 30 before you compare. The last row matters most: in its Fix a Leak Week guidance, the EPA says to look at a winter month, because there is little outdoor use then. "If a family of four exceeds 12,000 gallons per month, there could be serious leaks." That is about 16 CCF a month.

Read your meter and check for leaks

The meter is the source of every number on the bill, and you can read it yourself. At most houses it sits in a box in the ground near the curb, under a lid often marked "Water Meter", according to the Portland Water Bureau. Lift the lid carefully: Portland notes that lids can be heavy and that insects or small animals sometimes hide inside.

On the meter face you will find:

The register, the row of numbers. It counts in the unit printed on the face, such as cubic feet or gallons. The readings on your bill come from this register.
The sweep hand, which turns as water flows through the meter.
A leak dial on most residential meters: a small red or blue triangle, or a blue snowflake. It spins quickly when water runs and moves slowly when water drips.

The leak check, following Portland's steps and the EPA's two-hour test:

Turn off all water inside and outside: taps, showers, the washing machine, the dishwasher, sprinklers.
Look at the leak dial. If it turns, water is flowing somewhere. If there is no dial, watch the sweep hand.
If nothing moves, note the reading and the position of the hand. The EPA says to check the meter "before and after a two-hour period when no water is being used"; Portland suggests waiting several hours for a slow leak. If the reading changed, you probably have a leak.
To narrow it down, close the main shutoff valve inside the house, usually near the water heater, and open a tap to confirm the valve holds. If the meter still moves, the leak is between the meter and the house, possibly underground. If it stops, the leak is inside: toilets, faucets, appliances or hoses.

Why the dial and not the bill's number: a leak of 50 gallons a day loses about 4.2 gallons in two hours, which is only 0.56 cubic feet. A register that counts in whole cubic feet may not change, and one that shows whole CCF certainly will not. The dial and the sweep hand show far smaller flows.

For toilets, the EPA's test is food coloring in the tank: "If any color shows up in the bowl after 10 minutes, you have a leak." Flush afterwards so the color does not stain. A worn flapper is a common cause, and the EPA suggests replacing flappers at least every five years.

What leaks cost, from the same EPA page:

The average household's leaks waste more than 9,300 gallons a year, about 12.4 CCF.
A faucet dripping about once a second wastes over 3,000 gallons a year, about 4.0 CCF.
About 9 percent of homes have leaks that waste 50 gallons or more a day.
Fixing easily corrected leaks can save about 10 percent on the water bill.

In the example bill above, a 50-gallon-a-day leak adds 1,500 gallons, or 2.01 CCF, to the month. It pushes use past 15 CCF into the top tier and adds $13.04 to a summer bill. Had it run during the winter averaging months, it would also raise the winter average by the same 2.01 CCF, adding $12.03 of sewer charges to every month billed on that average.

When the bill jumps

Work through the likely causes in this order, from the cheapest to check:

Days in the period. A bill covering more days has more water and, with per-day fixed charges, a larger base fee. Compare usage per day, not per bill.
Usage in CCF or gallons. Compare with the same period a year earlier, not with last month, because the EPA notes that use is usually higher in summer. The percentage change calculator turns the two readings into a percentage.
Rates. Look for a rate change notice. Portland's water rate rose 8.1% on July 1, 2026, for example; a bill can rise while your usage stays flat.
Tiers and sewer basis. A small rise in use that crosses into a higher tier, or a month that counts toward a winter average, can raise the bill more than the extra gallons suggest.
Leaks. If usage rose without more outdoor watering, do the meter check above.

A simple log makes all of this easier. Note the dates, the usage and the total of each water bill in the free bill tracker, next to your electricity and gas bills, and give water its own line in the budget planner. If you share a home, the guide to splitting household costs covers how to divide utility bills, and the rent split calculator handles the arithmetic.

Frequently asked questions

How many gallons is 1 CCF of water?

About 748 gallons. CCF means 100 cubic feet, and a cubic foot holds 7.48052 US gallons, so 1 CCF is 748.05 gallons. HCF is the same unit under another name. To go the other way, 1,000 gallons is 1.3368 CCF.

Why is my sewer charge higher than my water charge?

Sewer rates per unit are often higher than water rates. In Portland, Oregon, for example, the 2026-27 residential sewer rate is $14.24 per ccf against $8.833 for water. Most homes have only one meter, so the EPA notes that many utilities bill sewer on the water entering the house. Some, like Portland, use your winter average so that summer garden water is not billed as sewage.

How much water does an average household use?

The EPA says the average American family uses more than 300 gallons a day at home and the average person about 82 gallons a day. A family of four uses around 10,000 gallons in 30 days, which is about 13.4 CCF. Use is usually higher in summer, and outdoor use can reach 60 percent of household use in dry regions.

How do I check for a water leak with my meter?

Turn off all water inside and outside, then look at the meter. A small leak dial (often a red or blue triangle) that spins means water is flowing. Without a dial, note the sweep hand or the reading, use no water for at least two hours, and check again. If it moved, you probably have a leak. Toilets are a common culprit: food coloring in the tank that shows up in the bowl within 10 minutes means the flapper leaks.

Why did my water bill go up?

Check four things in order: the number of days in the billing period, the usage in CCF or gallons compared with the same period a year earlier, the rates (Portland, for example, sets new rates each July 1), and leaks. If your usage rose without more outdoor watering, the EPA says that may point to a leak.

Sources

Written by Tobias. Updated October 22, 2026.