Coral Gables Water Hardness & Quality Report (2026)
Water Hardness
8.7 grains per gallon
Source
groundwater
pH Level
7.9
neutral = 7.0
Lead
0.003 mg/L
✓ Below action level
TDS
382.4 mg/L
Est. Daily Cost
$0.40
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 Coral Gables, your appliances are currently losing 20% efficiency due to mineral buildup.
| Appliance | In Coral Gables | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 4.7 yrs | 8.5 yrs | -45% |
| Washing Machine | 8.1 yrs | 12 yrs | -33% |
| Water Heater | 9.6 yrs | 15 yrs | -36% |
Regional Water Comparison
How Coral Gables compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Coral Gables, Florida | 149 mg/L | 7.3 ppt | 🟠 Hard | groundwater |
| Coconut Grove, Florida | 107.5 mg/L | 6 ppt | 🟡 Moderately Hard | groundwater |
| Coral Terrace, Florida | 154 mg/L | 7.4 ppt | 🟠 Hard | groundwater |
| Little Havana, Florida | 185.5 mg/L | 8.4 ppt | 🔴 Very Hard | groundwater |
| Glenvar Heights, Florida | 131.5 mg/L | 6.7 ppt | 🟠 Hard | groundwater |
National Benchmark
How Coral Gables compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Coral Gables | 149 mg/L | 🟠 Moderate |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Coral Gables's Water Unique?
Local geology and source profile
Coral Gables, Florida, in Miami-Dade County southwest of Miami — the 'City Beautiful,' one of the first planned cities in the United States (designed by George Merrick in the 1920s Mediterranean Revival style), home of the University of Miami, the Venetian Pool, and the Miracle Mile shopping district — draws its municipal water supply from the Biscayne Aquifer via the Miami-Dade Water and Sewer Department (WASD), applying reverse osmosis (RO) membrane treatment blended with conventionally treated supply. Water hardness in Coral Gables measures 149 mg/L — classified as moderately hard.
Coral Gables' relatively moderate supply — much softer than Allapattah (318 mg/L) and Kendale Lakes (259 mg/L) on the same WASD Biscayne system — reflects the Coral Gables distribution zone's higher RO treatment fraction. Coral Gables is an affluent planned municipality with high water quality expectations that have historically driven Miami-Dade WASD to provide a higher-quality RO-treated supply to the Coral Gables zone. The raw Biscayne Aquifer (Miami Limestone — Pleistocene calcareous oolitic limestone) carries 350–450+ mg/L raw hardness. The higher RO blend in the Coral Gables zone reduces the treated hardness to the moderate 149 mg/L — among the softest in the Miami-Dade system.
At 149 mg/L, Coral Gables residents face regular hard water challenges. Scale deposits form on faucet aerators, showerheads, and appliances within weeks — monthly descaling with citric acid solution is standard maintenance. Miami-Dade WASD consistently delivers water meeting all Florida DEP and EPA Safe Drinking Water Act requirements.
Geology & Source: Groundwater from the Biscayne Aquifer treated with reverse osmosis (RO) blending via the Miami-Dade Water and Sewer Department (WASD) — the southwest Miami Coral Gables Biscayne Aquifer Miami Limestone (Pleistocene) supply zone; moderately hard supply at 149 mg/L — reflecting a significant RO treatment fraction in the Coral Gables WASD distribution zone.