Las Vegas, NV water hardness: 280 mg/L (16 grains per gallon)
The Las Vegas Valley Water District (LVVWD) gives an average total hardness of 280 parts per million. That is very hard on the USGS scale (over 180 mg/L).
The numbers as LVVWD states them
| Measure | Average | Where |
|---|---|---|
| Total hardness | 280 ppm (mg/L) | Report p. 4 and Summary |
| Total hardness in grains per gallon | 16 gpg | Report p. 4 and Summary |
| Calcium | 75 ppm | Summary |
| Magnesium | 24 ppm | Summary |
The report tells customers to “set your water softener based on our water hardness (280 parts per million or 16 grains per gallon).” The year before, the 2025 report (2024 data) gave 291 ppm or 17 gpg. On 2026-10-26, LVVWD's water quality FAQ page showed both figures in different answers. We use the newer report.
Where the water comes from
About 90 percent comes from Lake Mead, fed by the Colorado River. The river's calcium and magnesium make the water hard. The other 10 percent comes from wells in the Las Vegas Valley aquifer, used mostly from April to October. LVVWD says homes in the northwest valley, or within several miles of its Charleston and Valley View offices, may get a blend of groundwater and lake water. The report gives one hardness figure for the system, not one per source.
What 280 mg/L means at home
Water softener
Program a softener at 16 gpg, as LVVWD advises. If the softener asks for compensated hardness and you have iron in your water, follow the softener manual. LVVWD's summary lists iron below 0.05 ppm, so most homes on district water can use 16 gpg.
Dishwasher
Set the dishwasher to its highest or next-highest hardness level. 280 mg/L is about 15.7 °dH (280 ÷ 17.8). Keep the rinse aid filled. If your model has a salt reservoir, keep that filled too. At this hardness, both help prevent white film on glasses.
Kettles, coffee makers, showers and water heaters
Expect fast white scale on anything that heats water. Kettles and coffee makers need regular descaling. USGS notes that scale in water heaters can reduce efficiency and raise heating costs. LVVWD states that the minerals “pose NO health risk.” Hardness is a scale and soap issue.
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Other Southern Nevada systems
LVVWD also publishes separate reports for Big Bend, Blue Diamond, Jean, Kyle Canyon and Searchlight on its reports page. Henderson and North Las Vegas run their own systems. This page covers the Las Vegas Valley system only.
Sources
- LVVWD, 2026 Water Quality Report (2025 data), page 4: https://www.lvvwd.com/assets/pdf/water-quality-report-las-vegas-valley-current.pdf
- LVVWD, 2026 Water Quality Summary (hardness, calcium, magnesium, iron): https://www.lvvwd.com/assets/pdf/water-quality-summary-las-vegas-valley.pdf
- LVVWD, 2025 Water Quality Report (2024 data, prior figure): https://www.lvvwd.com/assets/pdf/water-quality-report-las-vegas-valley-archive.pdf
- LVVWD, Water quality reports list: https://www.lvvwd.com/water-quality/reports/index.html
- USGS Water Science School, Hardness of Water: https://www.usgs.gov/water-science-school/science/hardness-water