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Filling a residential swimming pool with municipal water costs roughly $80 to $400 as of 2026. Most US utilities charge $3 to $9 per 1,000 gallons for water, and a typical backyard pool holds 15,000 to 25,000 gallons. If your sewer charge is billed off your water meter, and you do not request a pool-filling credit, expect to pay a similar amount again in sewer fees. Trucked-in water runs far higher, roughly $30 to $70 per 1,000 gallons delivered. Well water costs only the electricity to pump it, typically under $20.
How many gallons does my pool actually hold?
Volume drives everything else, so start here. For a round pool, gallons equal 5.9 times the diameter squared times the average water depth in feet. For a rectangle, it is length times width times average depth times 7.5. Note that manufacturers usually publish capacity at 90 percent fill, and you fill to about 4 inches below the top rail, so the real number is lower than the geometry suggests. These are the volumes people are actually filling.
| Pool | Water depth | Gallons | Water cost at $6 / 1,000 gal |
|---|---|---|---|
| 15 ft round above ground | 3 ft 8 in | ~4,900 | $29 |
| 18 ft round above ground | 4 ft | ~7,600 | $46 |
| 24 ft round above ground | 4 ft | ~13,500 | $81 |
| 27 ft round above ground | 4 ft | ~17,200 | $103 |
| 12 x 24 ft in-ground, 3-6 ft slope | 4 ft 6 in avg | ~9,700 | $58 |
| 16 x 32 ft in-ground, 3-6 ft slope | 4 ft 6 in avg | ~17,300 | $104 |
| 18 x 36 ft in-ground, 3-8 ft slope | 5 ft avg | ~24,300 | $146 |
| 20 x 40 ft in-ground, 3-8 ft slope | 5 ft avg | ~30,000 | $180 |
The exact gallonage for a 24-foot round is worked through in how many gallons is a 24 foot round above ground pool.
What do US water utilities actually charge per 1,000 gallons?
Water is billed per 1,000 gallons or per hundred cubic feet (CCF, which equals 748 gallons). As of 2026 the residential water commodity rate across most of the country falls between $3 and $9 per 1,000 gallons, with sewer often billed at a similar or higher rate on the same metered volume. Rates are set locally, so two towns 20 miles apart can differ by a factor of three. Your bill is the only authoritative source, and the EPA notes on its WaterSense pages that the average American family already pays roughly $1,000 a year for water and sewer combined.
| Region | Typical water rate per 1,000 gal, 2026 | What drives it |
|---|---|---|
| Southeast, Gulf Coast | $3 - $6 | Abundant surface water, low treatment cost |
| Midwest, Great Lakes | $4 - $8 | Aging distribution mains, lead service replacement |
| Northeast | $5 - $10 | Old infrastructure, high sewer charges |
| Desert Southwest | $3 - $12 | Steep tiered rates that punish high use |
| Coastal California | $7 - $15 | Imported water, drought surcharges, tier penalties |
| Rural well | Electricity only | Pump run hours, roughly $0.50 - $1.50 per 1,000 gal |
Those are ranges for orientation, not quotes. Pull your last bill, find the line marked water commodity charge and the line marked sewer or wastewater, and use those two figures.
Why does a pool fill push the price up so much?
Because most utilities use increasing block rates. You get a low rate on the first block of consumption, a higher rate on the next, and a punitive rate above that. A household using 6,000 gallons a month that suddenly adds 20,000 gallons is not paying the base rate on that water. It is paying the top tier, which in the Southwest and in California is routinely two to four times the first-block price. That is how a fill people expected to cost $90 arrives on the bill at $300.
Two practical moves. First, look up your utility tier breakpoints and, if the fill is large, split it across two billing periods so half the volume lands in each month's lower tiers. Second, ask whether the utility offers a one-time pool-fill rate exception. Many do for new pool construction, and almost none advertise it.
Should I ask my utility for a sewer credit before filling?
Yes, and this is the single most valuable thing on this page. Sewer charges are usually calculated from your water meter, since utilities cannot meter what leaves the house. Water that goes into a pool never reaches the sanitary sewer, so charging sewer on it is a billing artifact rather than a real cost. Most utilities will correct it, through a pool-filling adjustment, a summer sewer cap based on your winter average, or approval to install a deduct meter on an outside spigot. You almost always have to ask in advance and record meter readings. On a 20,000-gallon fill the credit is commonly worth $60 to $150.
When does trucked-in water make sense?
Bulk water delivery costs roughly $175 to $450 per load as of 2026, with most tankers carrying 4,000 to 6,000 gallons. That works out to about $30 to $70 per 1,000 gallons delivered, five to ten times the municipal rate. It is worth it in four cases: a well that cannot sustain the draw without silting up or running dry, drought restrictions that prohibit filling from the tap, a brand-new plaster in-ground pool that must be filled continuously without stopping, or a fill schedule measured in hours rather than days. Ask the hauler whether the water is potable and chlorinated, and ask for a hardness and iron reading. Well-sourced hauled water high in iron will stain a fresh liner within a week.
What costs come after the water?
The water bill is rarely the whole number. Budget for the chemistry needed to make a fresh fill swimmable.
- Start-up chemicals: $60 to $200. Chlorine, stabilizer, alkalinity increaser and calcium hardness increaser to bring a fresh fill to the CDC targets of at least 1 ppm free chlorine and pH 7.0 to 7.8.
- Cyanuric acid: a new fill has none, and without 30 to 50 ppm your chlorine burns off in hours — note that once stabilizer or stabilized chlorine is in the water the CDC raises its free chlorine minimum to 2 ppm. See why does my pool keep losing chlorine.
- Metal sequestrant: $20 to $40, essential on well or hauled water with any iron content.
- Heating the fill: ground-temperature water is cold. Raising 20,000 gallons by 10 degrees costs real money, worked out in how long it takes to heat a pool 10 degrees.
- Running the pump continuously for the first 48 hours to mix and filter, covered in how many hours a day you should run a pool pump.
Local water rates, sewer policy and drought rules differ in every jurisdiction, and some municipalities restrict or prohibit pool filling outright during declared shortages. Check your own utility and your city ordinances before you turn the tap on. Figures here are US dollars as of 2026.
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