How the calculation works
Cost = (gallons ÷ 1,000) × your rate, with sewer added if your utility charges it on water that never reaches the drain.
That sewer question is worth asking. Many utilities will waive or credit the sewer portion of a pool fill, since none of it enters the sewer system — but usually only if you contact them before or shortly after filling.
Worked example
A 20,000 gallon pool at $5 per thousand gallons costs $100 to fill. If sewer is charged at $6 per thousand on the same water, that adds $120 — more than the water itself, which is exactly why it is worth a phone call.
Assumptions
- A flat rate per thousand gallons, at the price you entered.
- Filling time ignores pressure drop, so a real fill usually runs a little longer.
Limitations
- Tiered water pricing is common, and a pool fill can push a household into a higher tier for the billing period — which this does not model.
- Water delivered by truck is priced completely differently and is often cheaper for a large fill in a metered or drought-restricted area.
- Drought restrictions in some regions prohibit filling outright at certain times of year.
Questions people ask
How much does it cost to fill a swimming pool?
At typical municipal rates, somewhere between $60 and $250 for a 20,000 gallon pool — the range is wide because water prices vary enormously. Sewer charges can double it if they are applied.
Can I avoid the sewer charge?
Often yes. Call your utility before you fill and ask — many have a pool-filling exemption or credit, since the water never enters the sewer. Some ask for a meter reading before and after.
Is a water truck cheaper?
Sometimes, particularly where water is expensive or tiered. It is also much faster — hours rather than a day or two. Get a quote per thousand gallons and compare it directly with the figure above.
How long does it take to fill a pool?
On a single garden hose at around 10 GPM, a 20,000 gallon pool takes about 33 hours. Two hoses halve it. Enter your flow rate above for your own figure.