What's in Las Vegas tap water
The Las Vegas Valley Water District publishes the minerals in valley water every year. Here is what that summary says, what each number means, and how Henderson's water compares.
The valley’s mineral numbers
The Las Vegas Valley Water District lists hardness alongside the other minerals it measured. All of these are from the district’s water quality summary published in 2026 (2025 data):
| What was measured | Parts per million | What it means at the tap |
|---|---|---|
| Total hardness | 280 | Scale on fixtures and appliances; 16 grains per gallon |
| Calcium | 75 | The main hardness mineral |
| Magnesium | 24 | The other hardness mineral |
| Sodium | 89 | Naturally present before any softening |
| Total dissolved solids | 591 | Everything dissolved in the water, minerals included |
Parts per million and milligrams per litre are the same measure. Divide by 17.1 for grains per gallon.
Lake Mead water, mostly
About 90 percent of the valley’s water comes from Lake Mead, fed by Colorado River snowmelt, and about 10 percent from wells in the Las Vegas Valley groundwater aquifer. The river picks up minerals on the way, which is where the hardness comes from. Because nearly the whole valley drinks the same blend, the district publishes one figure rather than one per neighborhood.
Henderson’s water
The City of Henderson’s 2026 annual report describes its water as “very hard”, with a typical hardness of 304 parts per million (18 grains per gallon), and recommends setting softeners between 16 and 19. All of Henderson’s water comes from the Colorado River through Lake Mead.
What these numbers don’t tell you
This page is about minerals: what makes water hard, and what a softener removes. For questions about whether the water meets drinking water standards, the utility’s full annual water quality report is the place to look; we only use it for hardness here.
Questions we get asked
- Does Las Vegas have hard water?
- Yes. The Las Vegas Valley Water District's water quality summary, published in 2026, gives total hardness of 280 parts per million, or 16 grains per gallon. Henderson's 2026 report gives a typical 304 ppm (18 gpg).
- What is the Las Vegas water hardness level in grains per gallon?
- 16 grains per gallon for most of the valley, the district's own figure. That is what to enter on a softener, unless you have tested your water.
- Why does Henderson have different numbers?
- Henderson runs its own water system and publishes its own report. Its water comes from the Colorado River through Lake Mead, treated at the Southern Nevada Water Authority's plants, and the city gives a typical hardness of 304 ppm.