How Much Does It Cost to Fill a Pool With Water?

Worried that filling your new pool will blow up your next water bill? For most families it won’t, because the cost to fill a pool with water usually runs about $25 to $105 on city water, depending on your pool’s size and local rate. That’s a small line against a project that costs tens of thousands, and an easy one to plan for. In the priciest states it can top $250, and trucked-in delivery adds a few hundred more.

The bill still catches people off guard. Homeowners budget carefully for excavation, the shell, and the electrician, then forget the one thing that turns an empty shell into a pool. A medium inground pool holds about 16,500 gallons, enough to nudge one water bill up by $75 or so.

What the fill costs comes down to three things: how many gallons your pool holds, where the water comes from, and a few tricks that keep the bill low. Curious how it fits the whole budget? Our breakdown of fiberglass pool hidden costs puts every line in one place.

Key Takeaways

• Filling a typical inground pool from city water costs roughly $25 to $105, and $150 to $250 or more in the priciest states.
• Pool volume drives the bill. A small pool holds about 6,000 gallons, a medium pool about 16,500 gallons, and a large pool about 22,500 gallons.
• Water delivery by truck costs far more, often $500 to $1,500 or more for a full pool, but it fills in hours and spares a well or a slow city line.
• A garden hose fills a pool in one to two days at 9 to 17 gallons per minute. Two hoses cut that time nearly in half.
• Fiberglass pools hold somewhat less water than comparable concrete or vinyl pools, which trims the fill cost and the ongoing chemical bill.

How Many Gallons Does It Take to Fill a Pool?

The number of gallons your pool holds is the single biggest factor in the fill cost, and it comes down to length, width, and average depth. To estimate it, multiply length by width by average depth, then multiply by 7.48, since a cubic foot holds 7.48 gallons of water. Average depth is the shallow end plus the deep end, divided by two.

Fiberglass pools tend to land in one of three size ranges. Here is roughly what a pool in each range holds, with a popular Pool Brokers USA model for each.

Pool Size	Example Pool Model	Dimensions	Average Depth	Approximate Gallons
Small	Charleston	10 ft x 20 ft	4 ft	6,000
Medium	Birmingham	14 ft x 35 ft	4 ft 6 in	16,500
Large	St. Louis	16 ft x 42 ft	4 ft 6 in	22,500

A fiberglass shell usually holds a little less water than the raw rectangular math suggests, and often less than a comparable concrete or vinyl pool of the same footprint. The curved walls, built-in steps, and tanning ledge take up volume that water would otherwise fill. Less water means a smaller fill bill today and fewer chemicals to balance over the years.

Quick Estimate Formula: (pool gallons ÷ 1,000) × your rate per 1,000 gallons ≈ fill cost. Example: 16,500 gallons at $4.60 per 1,000 gal → (16,500 ÷ 1,000) × $4.60 ≈ $76.

Still choosing a footprint? Compare our small fiberglass pool models, mid-size inground models, and large inground models to see how dimensions and gallon counts line up with your yard.

What Does It Cost to Fill a Pool With City Water?

Filling a pool from municipal water costs about $25 to $105 for most pool sizes at the national-average water rate. City water is billed by volume, most often per 1,000 gallons, so the bill is your pool’s gallons multiplied by your local rate.

Rates vary widely, so the same pool costs different amounts in different places. The table below shows the range across low, average, and high city-water rates, with the national average near $4.60 per 1,000 gallons.

Pool Size	Low Rate ($3 / 1,000 gal)	Average ($4.60 / 1,000 gal)	High Rate ($9 / 1,000 gal)
Small (6,000 gal)	$18	$28	$54
Medium (16,500 gal)	$50	$76	$149
Large (22,500 gal)	$68	$104	$203

A couple of billing quirks can nudge the number up, and local restrictions can limit your timing. Many utilities use tiered rates, so a large one-time fill can push part of your usage into a higher-priced tier for that cycle. Some also add a summer surcharge during peak demand, and both are worth a quick look at your rate schedule before you fill. During droughts, some municipalities also restrict or temporarily ban residential pool filling and can fine violations, so check local rules before you turn on the hose.

Pro Tip: Ask for a Sewer Credit. Many utilities bill sewer charges based on the water coming into your home, on the assumption that all of it goes back down the drain. Pool water doesn’t. Call your provider before you fill and ask for a one-time pool-fill sewer credit. Plenty will waive the sewer portion of that bill, which can noticeably lower what the fill costs you.

The tradeoff with a hose is speed. A standard garden hose delivers 9 to 17 gallons per minute, depending on hose length and water pressure, so a large pool can take a day or two of steady running.

How Much Does It Cost to Fill a Pool by State?

Water is not priced the same everywhere. The table below estimates the fill cost across the states we serve, using published state-average water rates from World Population Review and DataPandas converted to a per-1,000-gallon figure. Each dollar amount is that rate multiplied by the pool’s gallons. Treat these as directional. Local utility rates, fees, and tiered pricing vary, so your own water bill remains the reliable source.

State	Est. Rate / 1,000 gal	Small (6,000 gal)	Medium (16,500 gal)	Large (22,500 gal)
National average	$4.60	$28	$76	$104
Alabama	$2.70	$16	$45	$61
Arkansas	$2.70	$16	$45	$61
Delaware	$5.30	$32	$87	$119
Florida	$3.80	$23	$63	$86
Georgia	$3.10	$19	$51	$70
Indiana	$3.40	$20	$56	$77
Kentucky	$3.40	$20	$56	$77
Louisiana	$3.80	$23	$63	$86
Maryland	$5.60	$34	$92	$126
Mississippi	$3.90	$23	$64	$88
Missouri	$4.70	$28	$78	$106
North Carolina	$2.20	$13	$36	$50
Ohio	$3.10	$19	$51	$70
South Carolina	$3.40	$20	$56	$77
Tennessee	$4.00	$24	$66	$90
Virginia	$4.00	$24	$66	$90
West Virginia	$11.70	$70	$193	$263

The cost of water figures by state are real. A large pool that costs near $50 to fill in North Carolina can run several times that in West Virginia, which sits at the high end of published water rates. Across the Southeast and mid-Atlantic, a one-time fill for most families lands in a comfortable $20 to $130 window.

Want a real number for your yard rather than a state estimate? Request a free quote and we will map the full budget with you, water and all.

Well, City Water, or Delivery: Which Is Cheapest to Fill a Pool?

Where your water comes from shapes both the cost and the speed. Three sources cover almost every backyard: a garden hose on city water, a private well, or bulk water delivery by truck.

City water on a hose is the cheapest route for most suburban homeowners, at roughly $25 to $105 for a full pool. It is slow but steady, and it flows straight into your pool through the filter.

A private well changes the math. The water itself is close to free, but you pay for it in electricity to run the pump, usually $25 to $75 for a full fill. Well water also often carries dissolved metals like iron, copper, or manganese, which can stain a fresh pool green or brown when chlorine hits them. A quick metals test before you fill tells you whether to plan on a metal sequestering agent at startup. The real risk is the pump. Running a well flat-out for a day or two to fill thousands of gallons can overheat or damage it, and a replacement pump runs well into four figures. For a large fill, or any older well of uncertain capacity, many homeowners bring in a truck for the main fill and lean on the well only for top-offs.

Water delivery costs the most and saves the most time. Bulk haulers charge about $175 to $400 per truckload, and a truck carries roughly 5,000 to 6,000 gallons. For a full pool, that adds up to $500 to $1,500 or more. In return, the pool fills in hours instead of days.

Source	Typical Cost (Full Pool)	Speed	Best For
Garden hose, city water	$25 to $105	1 to 2 days	Most suburban homes on municipal water
Private well	$25 to $75 in electricity	1 to 2 days	Small fills, or paired with a truck for large pools
Water delivery	$500 to $1,500+	A few hours	Wells, low-pressure lines, drought limits, fast fills

For most homes on city water, the garden hose wins on price and the truck stays parked. Delivery earns its premium mainly when a well cannot sustain a long draw, a municipal line runs slow, or drought rules limit residential filling.

What Fiberglass Changes About Filling Your Pool

A fiberglass shell changes how you think about water management. You should almost never drain it fully, because the water inside counters the groundwater pressure pushing up from below. An empty shell in wet ground can shift or lift, so any repair that calls for lowering the water belongs to a pool professional who manages the groundwater first. In practice, that makes the big fill close to a one-time event rather than a recurring drain-and-refill expense.

Choosing fiberglass also eliminates the startup ritual that concrete and plaster pools require. A fresh plaster finish must be filled and brushed on a careful schedule as it cures, in line with Pool & Hot Tub Alliance guidance. A fiberglass gel coat surface does not cure underwater and produces no plaster dust, which leaves normal water balancing as the only step once the pool is full. Fewer chores and no resurfacing cycle are part of why fiberglass costs less to own over time, which our fiberglass pool maintenance guide covers.

Initial Fill vs. Seasonal Top-Off

The first fill is a one-time cost. Keeping the pool topped off through the season is the smaller, recurring one. Between evaporation, splash-out, and backwashing, an open pool can lose an inch or more of surface water a week in hot, dry weather. An inch across an average pool is a few hundred gallons. Over a summer, those top-offs add up to something in the $20 to $100 range for most families, well under the initial fill.

A cover is the biggest lever here. The EPA’s WaterSense program estimates a cover can prevent up to 95% of pool evaporation. A thermal blanket or a mesh safety cover slows evaporation sharply and holds heat overnight, so you refill less often and trim the heating bill. The fiberglass shell helps here too. Its non-porous gel coat holds heat and resists algae, so the water stays cleaner between top-offs.

How to Keep Your Fill Cost Down

A few moves keep the fill small, whether it is the first one or a mid-season top-off.

1. Call your utility first and ask for a pool-fill sewer credit before you start.
2. Fill during off-peak or shoulder seasons, when some utilities charge lower rates.
3. Run two hoses at once to cut fill time nearly in half and ease the strain on a well.
4. Check your rate schedule for tiers and summer surcharges so a big fill does not surprise you.
5. Cover the pool between swims to slow evaporation and refill far less often.

Frequently Asked Questions About Filling a Pool

Will Filling My Pool Spike My Water Bill?

For most homeowners it adds a modest bump, often $25 to $105 for a full fill on city water. A tiered rate or a summer surcharge can push part of a large fill higher, so check your rate schedule, and ask your utility about a one-time pool-fill sewer credit to keep the increase down.

Is It Cheaper to Fill a Pool With a Hose or Water Delivery?

A garden hose on city water is almost always cheaper, often $25 to $105 for a full pool. Water delivery costs $500 to $1,500 or more but fills in hours and protects a well or a slow city line, which makes it worth the premium for rural or low-pressure properties.

How Long Does It Take to Fill a Pool?

Most inground pools fill in one to two days with a standard garden hose, which moves 9 to 17 gallons per minute depending on hose length and water pressure. A small pool can finish in under a day, while a large one runs closer to two, or longer if a long hose or low pressure slows the flow. Running two hoses at once cuts that time nearly in half, and a water delivery truck can fill the pool in just a few hours.

Can I Fill My Pool With Well Water?

Yes, and the water itself costs little beyond the electricity to run the pump, around $25 to $75 for a full fill. The catch is that a long, high-volume draw can strain or damage the pump, so many homeowners bring in a delivery truck for a large fill and treat well water for extra minerals afterward.

Do I Have to Pay Sewer Charges When I Fill My Pool?

Often you can avoid them. Many utilities calculate sewer fees from water use, assuming it all goes down the drain, which pool water does not. Call your provider before filling and ask for a pool-fill sewer adjustment, and many will grant a one-time credit.

Does a Fiberglass Pool Cost Less to Fill Than Concrete or Vinyl?

Generally yes. A fiberglass shell’s curved walls, steps, and tanning ledge displace volume, so it holds somewhat less water than a comparable concrete or vinyl pool of the same footprint. Less water means a smaller fill bill up front and lower ongoing chemical and heating costs. See how the materials compare over time in our fiberglass vs. concrete pool cost breakdown.

The Bottom Line on Filling Your Pool

The cost to fill a pool with water is one of the friendlier numbers in the whole project. Figure about $25 to $105 from city water for most families, a little more where water runs expensive, and a few hundred dollars if you choose delivery for speed or to protect a well. It is a two- or three-figure line against a full pool project that runs into the tens of thousands, so knowing it early buys confidence, not sticker shock. Know your gallons, ask your utility about a sewer credit, and the fill becomes a line you planned for.

The larger, more rewarding decisions are the pool’s size, its shape, and how you want to bring it home. When you’re ready to put real numbers to your backyard, we’ll help you map the full picture, water and all, so nothing surprises you between here and your first swim. Request a free quote to get started.

Want to explore first? Browse our pool models and pool gallery, or check the areas we serve.