Gilroy Water Hardness & Quality Report (2026)
Water Hardness
6.5 grains per gallon
Source
mixed
pH Level
7.7
neutral = 7.0
Lead
0.005 mg/L
✓ Below action level
TDS
287.5 mg/L
Est. Daily Cost
$0.29
energy & soap waste
Source: USGS Water Quality Portal · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Gilroy, your appliances are currently losing 15% efficiency due to mineral buildup.
| Appliance | In Gilroy | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 6 yrs | 8.5 yrs | -29% |
| Washing Machine | 9.5 yrs | 12 yrs | -21% |
| Water Heater | 11.2 yrs | 15 yrs | -25% |
Regional Water Comparison
How Gilroy compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Gilroy, California | 110.5 mg/L | 5.2 ppt | 🟡 Moderately Hard | mixed |
| Morgan Hill, California | 67.5 mg/L | 4 ppt | 🟡 Moderately Hard | mixed |
| Watsonville, California | 182 mg/L | 7.3 ppt | 🔴 Very Hard | mixed |
| Hollister, California | 118.5 mg/L | 5.4 ppt | 🟡 Moderately Hard | mixed |
| Prunedale, California | 67 mg/L | 4 ppt | 🟡 Moderately Hard | mixed |
National Benchmark
How Gilroy compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Gilroy | 110.5 mg/L | 🟡 Low |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
Bring Badger-quality water to your Gilroy home
Shop water softeners on Amazon.com →
What Makes Gilroy's Water Unique?
Local geology and source profile
Gilroy, California, the Santa Clara County seat of the southern Santa Clara Valley — the 'Garlic Capital of the World,' host of the Gilroy Garlic Festival (the world's largest garlic festival), a major South Bay agricultural and growing residential community — draws its municipal water supply from the Llagas sub-basin of the Santa Clara Valley Groundwater Basin and State Water Project (SWP) imports via the City of Gilroy Engineering Division Water and the Santa Clara Valley Water District (Valley Water). Water hardness in Gilroy measures 110.5 mg/L — classified as moderately hard.
Gilroy's moderate hardness reflects the southern Santa Clara Valley's calcareous groundwater and SWP import blend. The Llagas sub-basin (the southern Santa Clara Valley's groundwater basin in the Gilroy–Morgan Hill area — Quaternary alluvial fan deposits from Uvas Creek, Llagas Creek, and the Diablo Range foothills) receives: SWP Delta-Mendota Canal imports through percolation ponds (moderately soft SWP water); and local Diablo Range recharge (Coast Range Franciscan Complex and Great Valley Sequence calcareous formations — the Diablo Range's Cretaceous calcareous marine sandstone and shale contributing moderate dissolved calcium). The blended Llagas sub-basin supply produces the moderate 110.5 mg/L at Gilroy.
At 110.5 mg/L, Gilroy residents encounter moderate scale accumulation. Faucet aerators and showerheads develop deposits after several months — monthly cleaning with citric acid solution is practical maintenance. City of Gilroy Engineering Division Water and Valley Water consistently deliver water meeting all California SWRCB and EPA Safe Drinking Water Act requirements.
Geology & Source: Groundwater from the Santa Clara Valley Water District (Valley Water) Uvas Reservoir–Llagas sub-basin and State Water Project (SWP) import via the City of Gilroy Engineering Division Water — the Santa Clara County Gilroy–Llagas sub-basin Quaternary alluvial aquifer at the Diablo Range–Santa Clara Valley interface; moderately hard supply at 110.5 mg/L in Santa Clara County.