Hardest Water in Minnesota
16 cities ranked by water hardness. Woodbury tops the list at 271 PPM.
Minnesota's water hardness varies significantly by city and water source. The state average across our database is 216 PPM, which is very hard. Most Minnesota households will benefit from a water softener. 88% of cities we track in Minnesota have hardness above 120 PPM.
Woodbury has the hardest water at 271 PPM (15.8 GPG). At this level, expect visible scale on faucets, reduced water heater efficiency, and higher soap usage. A salt-based water softener typically pays for itself within 12-18 months in energy and consumable savings. Duluth has the softest water at just 21 PPM. No softener is needed.
| # | City | PPM | GPG | Level | Softener? |
|---|---|---|---|---|---|
| 1 | Woodbury | 271 | 15.8 | Extremely Hard | Yes |
| 2 | Mankato | 270 | 15.8 | Extremely Hard | Yes |
| 3 | Lakeville | 265 | 15.5 | Extremely Hard | Yes |
| 4 | Eden Prairie | 260 | 15.2 | Extremely Hard | Yes |
| 5 | Bloomington | 257 | 15 | Extremely Hard | Yes |
| 6 | Burnsville | 255 | 14.9 | Extremely Hard | Yes |
| 7 | Plymouth | 254 | 14.9 | Extremely Hard | Yes |
| 8 | Maple Grove | 250 | 14.6 | Extremely Hard | Yes |
| 9 | Blaine | 245 | 14.3 | Very Hard | Yes |
| 10 | Brooklyn Park | 240 | 14 | Very Hard | Yes |
| 11 | St. Cloud | 230 | 13.5 | Very Hard | Yes |
| 12 | Minneapolis | 200 | 11.7 | Very Hard | Yes |
| 13 | Rochester | 200 | 11.7 | Very Hard | Yes |
| 14 | St. Paul East | 170 | 9.9 | Hard | Recommended |
| 15 | St. Paul | 68 | 4 | Moderately Hard | Optional |
| 16 | Duluth | 21 | 1.2 | Slightly Hard | No |
Frequently Asked Questions
What is the average water hardness in Minnesota?
Across 16 cities in our database, the average water hardness in Minnesota is 216 PPM (12.6 GPG). This ranges from 21 PPM in Duluth to 271 PPM in Woodbury.
Do I need a water softener in Minnesota?
It depends on your city. 88% of Minnesota cities in our database (14 of 16) have hardness above 120 PPM where a softener provides measurable benefit. Check your specific city above.
Which Minnesota city has the softest water?
Duluth has the softest water in Minnesota at 21 PPM (1.2 GPG). No water softener is needed at this level.
What causes hard water in Minnesota?
Hard water in Minnesota is caused by dissolved calcium and magnesium from the local geology. Limestone and dolomite bedrock are the primary sources, dissolving minerals into groundwater and surface water as it flows through the rock.