Understanding the Costs of Filling Your Swimming Pool
One of the significant initial expenses associated with owning a swimming pool is the cost of filling it with water. This can be particularly pronounced for new installations that require thousands of gallons to reach full capacity. Additionally, pool owners who are reopening their pools in the spring often face similar costs. Many pools are partially drained below the skimmer to prevent water pipes and hoses from freezing during the colder months. Depending on the pool’s size, this could mean needing several hundred to thousands of gallons of water to replenish it after a winter break.
The average cost for water used in households ranges from $4 to $10 per 1,000 gallons. When filling a swimming pool after installation, the amount of water needed can vary widely—from just a few thousand to over 20,000 gallons, depending on the size of your pool. An empty swimming pool can incur a fee of anywhere from $75 to more than $200 for filling, based on its average size.
Calculating Your Pool’s Water Capacity
Before you can estimate the cost of filling your pool, you first need to determine its water capacity in gallons. The easiest way to find this information is through the materials provided by the manufacturer after your pool purchase. If you do not have access to that documentation, you can perform a simple calculation to find out your pool’s capacity.
Formula for Calculating Water Capacity
To calculate the water capacity of your swimming pool, use the appropriate formula based on the shape of your pool:
If you’re interested in how long it takes to fill your swimming pool, consider checking out my older article titled “How Long Will It Take to Fill My Swimming Pool.”
Circular Pools
For circular pools, which include both round and oval shapes, use the following formula:
Length (A) x Length (B) x Depth x 5.9 = Total Water Volume
For round pools, Length A and Length B will be the same value. For oval pools, these dimensions will differ due to the varying lengths of the pool’s sides.
Rectangular Pools
For square or rectangular pools, the formula changes slightly:
Length (A) x Length (B) x Depth x 7.5 = Total Water Volume
If your pool has varying depths (shallow and deep ends), use the average depth for your calculations to achieve a more accurate estimate of water volume.
Estimating the Cost to Fill Your Pool
Below is a chart that outlines the estimated costs based on a water price of $9 per 1,000 gallons. Your actual cost may differ, so feel free to adjust accordingly using the calculator above if you know your specific rate:
| Gallons Of Water |
Cost To Fill With Water |
| 5,000 | $45 |
| 10,000 | $90 |
| 15,000 | $135 |
| 20,000 | $180 |
Once you have determined your pool’s total capacity in gallons, the next step is to find out the rate of your water and sewer charges. If you are connected to city water, this information can usually be found on your water bill or the city’s website.
Example: My Water Bill Rates
For instance, in Midwest City, OK, the current water billing structure (as of January 7, 2019) includes the first 0-2,000 gallons of water as part of the initial charge. This means that you are billed for a minimum of 2,000 gallons regardless of whether you use any water or the full amount. The same applies to sewer charges.
Since the base charge is mandatory, we will not include it when calculating the cost to fill the pool. After the first 2,000 gallons, there’s a fee of $4.11 for each additional 1,000 gallons of water and a $4.28 charge per 1,000 gallons of sewage use. Although filling the pool will not affect the sewer charges, my city still applies the sewage fee during this process. It’s advisable to check with your local water provider to see if you can receive an exemption for sewage fees when filling a pool; however, most municipalities do not allow this.
To calculate my additional water bill charges, I simply add the sewage fee and the water fee: $4.11 + $4.28 = $8.39. This means for every 1,000 gallons of water used, my cost will be $8.39. For a pool that holds 20,000 gallons, the additional charge to my water bill would be:
(20,000 gallons / 1,000) x $8.39 = $167.80.
Using a Water Well
Some homeowners opt to use a water well instead of city water. If you fall into this category, you won’t have a water bill; however, running your well pump will increase your electricity costs. When filling a pool over an extended period, your electric bill may rise significantly due to the pump’s energy consumption.
To estimate this cost, determine how much electricity your well pump uses per 1,000 gallons and calculate the expense accordingly. Knowing your pump’s wattage and model will help in this assessment. While generally, the cost of using a well pump is lower than city water, exceptions may apply.
If you’re unsure of the additional cost per 1,000 gallons for electricity, you can use city water rates as a reference for a rough estimate, keeping in mind that well pump owners do not incur sewage fees.
Refilling Partially Drained Pools
If you are only topping off your pool due to a partial drain, you will likely only need to refill around 15% of the pool’s total volume. For example, if you have a 20,000-gallon pool, you may need to add between 1,000 to 3,000 gallons of water, depending on how low the water level has dropped.
During the typical swimming season, you may also need to replenish water to account for evaporation, minor leaks, and splashes made during fun activities. Such refills typically won’t be significant enough to noticeably impact your water bills.
Measure for Accuracy
To determine how many gallons of water you’ll need to refill, along with the potential costs, use a tape measure. Measure the distance from the water’s surface to the top of the pool. If your pool is covered, take this measurement before removing the cover, placing the end of the tape measure on the cover and measuring to the top of the pool.
If you find that the distance is 1.5 feet from the cover to the filling point, simply plug this measurement into your calculation. The depth will be consistent across all sides of the pool, making it easy to determine the cost to refill your partially drained pool.
A swimming pool is a source of joy and a great family activity. With this information, you can avoid any unexpected charges associated with filling your pool. So, get ready to fill it up and enjoy a refreshing swim!