Filling a Pool in Henderson: Your Tap Water’s Starting Numbers
Filling a pool in Henderson means starting from City of Henderson Utility Services’s water — which is very hard at roughly 304 mg/L total hardness (about 17.8 grains per gallon). Here is what those published numbers actually do to a pool — and what they do not.
Which way this water pushes a pool
Reading scale-versus-etch direction needs hardness, alkalinity and pH together, and City of Henderson Utility Services does not publish alkalinity or pH. That direction cannot be computed from public data for this city and we are not going to guess it — a drop-count test kit reads all of it in about five minutes once the pool is full.
The top-off arithmetic
Evaporation removes pure water and leaves the minerals behind, so make-up water re-adds Henderson hardness every time. Replacing one full pool volume through top-off adds roughly another 304 ppm; starting from a fresh fill at about 304 mg/L, that reaches the 400 ppm ceiling after about 0.3 pool volumes of make-up water — less than one full pool volume — a hot-summer pool can work through that in a season or two, not decades. No city on this list of 27 has a shorter top-off budget.
Evaporation-only and deliberately the fastest case: splash-out, backwash and rain all dilute, and this uses published total hardness rather than the calcium fraction a kit reads (how this is calculated).
Why Henderson water is like this
The single most useful thing a Henderson pool owner can know is that Henderson’s fill water chemistry is not really Henderson’s – it is Lake Mead’s, arriving through the same two SNWA plants that serve Las Vegas. Henderson buys finished water; it does NOT operate a drinking-water treatment plant of its own. The plants Henderson does run are wastewater facilities on the other end of the pipe: the Kurt R.
Segler Water Reclamation Facility (built 1994, upgraded 2008, 32 million gallons per day, activated sludge with UV disinfection) and the Southwest Water Reclamation Facility (2012, 8 mgd capacity, membrane bioreactor). Neither touches drinking water.
That means nothing in Henderson’s own infrastructure adds or removes hardness, alkalinity, or pH – the numbers are set upstream by Colorado River basin geology (limestone and evaporite formations dissolved along the river’s course), concentrated by evaporation in Lake Mead, and then passed through SNWA filtration and disinfection that removes pathogens and leaves minerals intact.
So a Henderson pool sees essentially Las Vegas fill water, and the practical differences between the two cities are NOT chemical – they are regulatory and billing differences, which are substantial and are covered below. The City’s own site does state the hardness is typically 304 ppm, about 18 grains per gallon, and categorizes it ‘very hard’; that figure was seen in search result text rather than read directly off the City page, so treat the exact value as secondary and rely on the project’s own collected numbers.
Henderson operates NO drinking-water treatment plant. Finished water comes from SNWA’s Alfred Merritt Smith or River Mountains Water Treatment Facility, described by the City as ‘a sophisticated filtration and disinfection process.’ Henderson’s own plants are wastewater: the Kurt R.
Segler Water Reclamation Facility (1994, upgraded 2008, 32 mgd, activated sludge removing organics, solids, ammonia and phosphorus, tertiary phosphorus removal and sand filtration, primary disinfection by ultraviolet light with chlorination/dechlorination as backup) and the Southwest Water Reclamation Facility (2012, 8 mgd capacity, currently just over 4 mgd, headworks plus activated sludge plus membrane bioreactor, chlorinated and distributed to reclaimed-water customers in the southwest of the city).
No softening or hardness-reducing step exists anywhere in Henderson’s potable chain.
Background sources: cityofhenderson.com, snwa.com.
Before you drain or refill in Henderson
- MANDATORY PHONE CALL – the City’s Utility Services FAQ, answering ‘I need to drain and refill my pool; do I need to contact the City of Henderson?’, says: ‘Yes, please call 702-267-5900 so a call center representative can flag your account for the extra water use. There is no discount for the extra water use.’ Note this directly contrasts with SNWA’s regional guidance that no notification is needed – Henderson is stricter than the regional default.
- COMBINED SIZE CAP – from the City’s Landscape Restrictions page: ‘As of 09/19/2022 the combined water surface area for single-family residential swimming pool, spa, and hot tub cannot exceed 600 square feet of surface area of water.’ The word COMBINED matters: unlike the LVVWD phrasing, Henderson aggregates pool plus spa plus hot tub against the single 600 square foot budget.
- DRAINING – ‘Make sure to drain into your sanitary sewer clean out port located on your property.’ The City suggests asking a neighbor if you cannot find your port, since layouts repeat. ‘An alternative to the sanitary sewer port would be a slow drain into a bathtub. Do NOT drain into the street. This is a water waste violation.’ The water waste page lists ‘Draining a swimming pool or spa into the street rather than your designated sanitary sewer port where the water can be recycled’ as a named example of water waste.
- SEPTIC EXEMPTION – ‘Henderson customers on septic systems are exempt from this restriction, but are required to dechlorinate the water and submit a request prior to discharging water to the gutter.’
- THE LONG MEMORY – this is the sharpest Henderson-specific detail: ‘Water waste violations are cumulative within an 18-month period. Violations for improper draining of pools or spas are cumulative within a 36-month period.’ Pool draining violations stack against you for twice as long as any other kind of water waste.
- FINES – administrative fines by meter size (most Henderson residential customers have a meter of 1 inch or less): for 1 inch or less, $80 for the 1st violation, $160 for the 2nd, $320 for the 3rd, $640 for the 4th, and $1,280 for the 5th and beyond; for meters over 1 inch up to 3 inches, $160 through $2,560; for 3 inches or greater, $320 through $5,120. Process: a courtesy warning letter first, then a Notice of Violation and fine on a second violation within 18 months, with continuing letters and fines until corrected. Fines do not preclude further civil or criminal enforcement under HMC Chapter 14.21.
- APPEALS – a written Request for Reconsideration must be delivered personally or by registered or certified mail to the Director of Utility Services and must be received or postmarked on or before the 11th day after the City’s action. Mail to City of Henderson, Attention Director of Utility Services, P.O. Box 95050 MSC 124, Henderson NV 89009-5050.
- Regional SNWA pool draining mechanics also apply: 12 gallons per minute maximum discharge, never into a septic tank, find the 3-to-4-inch clean-out port. Henderson’s SNWA-listed pool contact number is 702-267-5900.
Rules change and enforcement varies — confirm with your water provider before draining or refilling. Nothing here is legal advice.
Worth a look next door
- Filling a pool in Los Angeles — The other end of the scale: Los Angeles gets about 1.2 pool volumes of top-off against 0.3 pool volumes here.
Source: City of Henderson 2025 Water Quality Report (CCR webpage, CY2024 data) + archived 2024 Water Quality Report PDF (CY2023 data) (2025 (CY2024 data); chlorine residual from 2024 WQR (CY2023) report data), accessed 2026-08-11. Values are the utility’s published system-wide figures; your tap can vary by service zone and season.
Data page generated 2026-08-15. Part of the pool fill-water lookup.