Water hardness in Cathedral City
14 gpg very hard
Tap water in Cathedral City is very hard: 14 gpg (240 mg/L · 13.4 °dH · 24 °fH).
Source: Desert Water Agency 2025 Water Quality Report (delivered 2026) (2025) · data checked 2026-10-20
Range across supply zones: 94–340 mg/L.
The figure comes from Desert Water Agency (DWA), which serves only part of Cathedral City, so other parts of the city may be supplied by a different utility with different numbers. DWA's 2025 report lists its groundwater at 240 mg/L (14.0 gpg), with wells ranging from 94 to 340 mg/L (5.5 to 19.9 gpg) over 2022 to 2025. That is very hard water, and heavy scale on heaters and fixtures is likely. Check your own water bill to see which utility serves your address.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 14 gpg |
|---|---|
| Utility | Desert Water Agency (DWA) |
How Cathedral City compares
- Tap water in Cathedral City is 55 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 402 of 1372 in the United States (1 = hardest); 70 % of these cities have softer water.
- In California it is number 81 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: Palm Desert, 10 km away (7 gpg).
- Nearest city with clearly harder water: Hemet, 49 km away (18.1 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Cathedral City
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 13 °dH |
| AEG / Electrolux | 3 |
| Beko | 4th |
| Hoover | S2 |
| LG | H2 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Cathedral City water hard or soft?
It is very hard: 240 mg/L as CaCO₃ (14 gpg, 13.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Cathedral City safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Cathedral City water?
14 gpg, equal to 13.4 °dH, 24 °fH or 240 mg/L calcium carbonate.
What dishwasher salt setting should I use in Cathedral City?
For 240 mg/L (13.4 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Cathedral City?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Desert Water Agency 2025 Water Quality Report (delivered 2026) (2025). Method: figure published by the water supplier. Desert Water Agency 2025 Water Quality Report (delivered 2026) · Outdated figure? Tell us