Prosper's new volumetric water rates take effect October 15, 2026, and residents will see them on their bills for the first time in November. News coverage illustrated the 13.95% water increase with an average household using 13,000 gallons a month. The ordinance also changed the gallon levels where each pricing tier starts. For a home that uses 50,000 gallons in a summer month, the volumetric water charge rises about 36%.
That matters most in places like Whispering Farms, where a March 2026 Planning and Zoning staff report describes one Phase 2 lot at 5.1 acres. If you're comparing an estate lot with a standard suburban lot elsewhere in Prosper, the summer water bill is the carrying cost that changed most this fall. The average-household example won't show you that.
Where the 13.95% Comes From
Prosper Town Council unanimously approved Ordinance 2026-40, an amendment to the Town's fee schedule, at its September 8, 2026 meeting, according to the council minutes. Community Impact reported that water rates rise 13.95% and wastewater rates rise 17.96%. The outlet used the staff presentation's example of a household using 13,000 gallons of water and 7,000 gallons of wastewater, whose combined monthly bill goes from $177.70 to $205.
That example is accurate. It also describes a household that never gets past the second pricing tier. The Town's rate consultant, NewGen Strategies and Solutions, said in its study that it was told to design a volumetric structure "that promotes conservation of water." Its answer was to tighten the tier bands so the top tier starts at 35,000 gallons instead of 80,000. A conservation structure is built to charge more for high use. The 13,000-gallon example, by definition, isn't high use.
The Breakpoints Moved More Than the Prices Did
Here are the residential water tiers before and after. The old figures come from the Town's posted schedule for the billing cycle after October 15, 2025. The new ones come from the text of Ordinance 2026-40.
| Tier | Old band, gallons | Old rate per 1,000 | New band, gallons | New rate per 1,000 |
|---|---|---|---|---|
| 1 | 0 to 10,000 | $4.83 | 0 to 10,000 | $5.50 |
| 2 | 10,001 to 40,000 | $7.23 | 10,001 to 20,000 | $7.98 |
| 3 | 40,001 to 80,000 | $10.86 | 20,001 to 35,000 | $9.98 |
| 4 | Over 80,000 | $16.28 | 35,001 and up | $14.97 |
The prices in tiers 3 and 4 actually went down. The increase for heavy users comes from where those tiers now start. Under the old schedule, every gallon from 10,001 through 40,000 was billed at $7.23 per 1,000. Now gallons 10,001 through 20,000 cost $7.98, gallons 20,001 through 35,000 cost $9.98, and gallons 35,001 through 40,000 cost $14.97. Gallons 35,001 through 80,000 used to cost $7.23 or $10.86, and now every one of them costs $14.97.
Also note that the Town's Residential Water Rates webpage still showed the 2025 schedule when this research was done. The ordinance is the document that governs the new rates.
The Same Month Under Both Schedules
Here are a few monthly usage levels run through both tables. These figures cover the volumetric water charge only. The base charge and wastewater are separate. The usage levels are examples, not measured use for any particular home.
- 13,000 gallons. About $69.99 before, $78.94 after. That's an increase of $8.95, or roughly 13%, close to the headline.
- 25,000 gallons. About $156.75 before, $184.70 after. That's up $27.95, or roughly 18%.
- 50,000 gallons. About $373.80 before, $509.05 after. That's up $135.25, or roughly 36%.
- 80,000 gallons. About $699.60 before, $958.15 after. That's up $258.55, or roughly 37%.
- 100,000 gallons. About $1,025.20 before, $1,257.55 after. That's up $232.35, or roughly 23%.
The percentage increase peaks between about 35,000 and 80,000 gallons. That band now falls entirely into the new top tier. Under the old schedule it was mostly billed at second- and third-tier prices. Above 80,000 gallons, the lower top-tier price starts pulling the percentage back down. The household that takes the biggest proportional hit is the one using somewhere between two and six times the average, and that's the range where irrigation on a large lot can land in a hot month.
The base charge goes up too, and it depends on meter size. A 1-inch meter goes from $24.02 to $27.37 a month. A 1½-inch meter goes from $48.03 to $54.73, and a 2-inch meter from $76.80 to $87.51. The ordinance dates the new base charges October 16, 2026, one day after the new volumetric rates.
Why Wastewater Follows a Different Calendar
The wastewater increase is the bigger percentage, at 17.96%. It works differently for a large lot, though. The new residential wastewater charge is a $44.72 monthly minimum plus $7.71 per 1,000 gallons, up from $37.91 and $6.54. Under Ordinance 2026-40, the volumetric part is billed on average water use in December, January, and February.
Because of that winter average, a 50,000-gallon July doesn't turn into 50,000 gallons of wastewater charges. For an estate property, the summer increase falls mostly on the water side of the bill. It also means the coming December-through-February period is the first winter average measured at the new rates.
The Town's watering guidelines fit that calendar. From November 1 through March 31, the Town recommends watering no more than once a week and not watering during rain or freezing temperatures. Overseeding with cool-season grass is prohibited. From April 1 through October 31, permitted watering days are assigned by zone: Zone 1 on Monday and Thursday, Zone 2 on Tuesday and Friday, and Zone 3 on Wednesday and Saturday. The guidelines also say to avoid running sprinklers between 10 a.m. and 6 p.m.
One caveat applies to Whispering Farms in particular. Town sources don't say whether its homes are on Town sewer, private septic systems, or a mix. Prosper's 2020 comprehensive plan says large-lot homes built in town before 2005 generally coincided with septic requirements that set a one-acre minimum lot size, but it doesn't name this subdivision. The wastewater math above applies only to homes billed for Town wastewater service. Whether a particular address has that service is something to confirm for that address.
What This Changes in a Lot Comparison
When buyers compare a Whispering Farms estate with a home on a standard lot elsewhere in Prosper, they usually compare HOA dues, property taxes, and insurance. Water often gets treated as a rounding error. Under the old schedule, it mostly was one. A home could use 40,000 gallons and never pay more than $7.23 per 1,000 gallons past the first tier.
Under Ordinance 2026-40, the same base use of 13,000 gallons costs about $9 a month more. A summer month of irrigation can cost well over $100 more. So the gap between a large lot and a small one grows during the months a large lot uses the most water. That gap shows up in a seller's past utility bills, not in the listing details. Three things explain how a specific property behaves under the new schedule:
- Summer-month water use, from the bills, compared against the 20,000- and 35,000-gallon breakpoints
- Meter size, which sets the base charge
- Wastewater service, meaning whether the home pays Town wastewater and what its winter average looked like
One more timing detail. Bills issued before November 2026 reflect the old rates. A summer 2026 bill shows the gallons a property used, but its dollar total understates what those same gallons will cost after October 15.
The Increases Continue After This Year
Community Impact reported that infrastructure investment is the main driver. That includes nearly $33 million in debt the Town expects to issue over the next two years for the expansion of the Doe Branch Water Reclamation Plant, a $269 million joint project with the City of Celina. The outlet also reported that this year's increase is the largest of several planned through fiscal year 2030-31. Town officials hope to fund a US 380 waterline relocation without new debt, which could ease future increases.
The rate study projects water increases of 7.10% in FY 2028, 6.75% in FY 2029, 5.02% in FY 2030, and 4.80% in FY 2031. Wastewater is projected to rise 8.89%, 8.17%, 3.25%, and 3.15% over the same years. Those are projections from the study, not adopted rates. If later increases are applied across all tiers, homes whose usage reaches the 35,000-gallon tier will keep paying the most in dollar terms.
FAQ
When do the new rates show up on bills? The new volumetric rates take effect October 15, 2026, and the new base charges take effect October 16. Community Impact reported that residents will first see them on November bills.
Did the price per gallon go up at every level? No. The first two tiers cost more per 1,000 gallons. The third and fourth tiers cost less per 1,000 gallons than the old third and fourth tiers, but they now start at 20,001 and 35,001 gallons instead of 40,001 and 80,001.
Does summer irrigation raise the wastewater bill? Not for the volumetric part. For residential accounts, that part is based on average use in December, January, and February.
If you're pricing out a Whispering Farms estate or getting ready to sell one, Rebecca Lee Group can run the property's past utility history through Prosper's new tiers. That way the carrying-cost comparison reflects what the water actually costs after October 15. Get Your Free Home Valuation, and we'll include the utility math in the review.
This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.
