How hard is the water in Joshua Tree, CA?

Tap water hardness
70mg/L
4.1gpg
Moderately hard

Reported by Joshua Basin Water District · June 2025

CA typical
121 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

Tap water in Joshua Tree has about 70 mg/L of hardness, which is 4.1 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Joshua Basin Water District, dated June 2025.

Joshua Tree on the hardness scale, with nearby cities
060120180240300360+CA typical 121Yucca Valley: 110 mg/LYucca Valley 110Twentynine Palms: 111 mg/LTwentynine Palms 111Thousand Palms: 113 mg/LThousand Palms 113Desert Palms: 113 mg/LDesert Palms 113Bermuda Dunes: 113 mg/LBermuda Dunes 113Cathedral City: 138 mg/LCathedral City 138Palm Springs: 138 mg/LPalm Springs 138Rancho Mirage: 138 mg/LRancho Mirage 138Garnet: 213 mg/LGarnet 213Desert Hot Springs: 213 mg/LDesert Hot Springs 213Joshua Tree 70mg/L as calcium carbonate060120180240300360+CA 121Yucca Valley: 110 mg/LYucca Vall. 110Twentynine Palms: 111 mg/LTwentynine. 111Thousand Palms: 113 mg/LThousand P. 113Cathedral City: 138 mg/LCathedral. 138Garnet: 213 mg/LGarnet 213Desert Hot Springs: 213 mg/LDesert Hot. 21370 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Joshua Tree sits 51 mg/L below the typical California figure of 121. None of the 10 nearest cities we track has softer water. The range nearby runs from 110 mg/L in Yucca Valley to 213 in Garnet.

What 70 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Joshua Tree

3 people × 75 gallons a day × 4.1 gpg = 927 grains a day. A 24,000-grain unit regenerates about every 25 days.

Size it for your household

EPA record for Joshua Tree's water system

Joshua Basin Water District · PWSID CA3610025

No health-based violations since 2016

Serves about 6,489 people from groundwater.

Health-based
0
Monitoring or reporting
0
Open now
0

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Joshua Tree water hard?

Somewhat. It measures about 70 mg/L (4.1 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Joshua Tree in grains per gallon?

About 4.1 gpg. One grain per gallon equals 17.1 mg/L, so 70 mg/L divided by 17.1 gives 4.1.

What size water softener do I need in Joshua Tree?

For 3 people using 75 gallons each per day, 4.1 gpg works out to about 927 grains a day. A 24,000-grain softener covers that with a regeneration about every 25 days.

Has the Joshua Tree water system had EPA violations?

EPA records show no health-based violations for Joshua Basin Water District since 2016.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (utility report, June 17, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.