How hard is the water in Winona County, MN?
16.4 grains per gallon
A softener will pay its way here.
The median hardness measured in Winona County, MN is 280 mg/L as calcium carbonate, which is 16.4 gpg. That is very hard on the USGS scale. It comes from 198 samples at 21 sites between 1990 and 2025, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 11 and 18.1 gpg. The whole middle of that range gives the same answer, so a test of your own tap is unlikely to change it. Confidence in the county figure: high (how it is measured).
What to do next
At 16.4 gpg a softener pays its way here. Before you buy, check the quoted unit's grain capacity against the sizing table below, and ask whether it regenerates on demand, which uses less salt than a timer. Call your utility for its own report if you are on city water.
More on sizing a softener for your household.
From 0.6 to 19.8 gpg
The softest single sample on record in Winona County was 9.8 mg/L and the hardest 339 mg/L, a 35-fold gap. The top quarter of sites read above 18.1 gpg and the bottom quarter below 11 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 12.1 gpg, rivers and lakes 16.9 gpg
1 groundwater samples from 1 wells put the median at 207 mg/L. 197 surface samples from 20 sites put it at 289.5 mg/L. In Winona County the rivers and lakes come out 4.8 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. A utility here that draws from the aquifer can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 357 lb of salt a year (9 bags of 40 lb, about $64), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $164 a year.
Sizing at 16.4 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 984 | 24,000 | 120 lb |
| 2 | 1,968 | 24,000 | 239 lb |
| 4 | 3,936 | 32,000 | 479 lb |
| 6 | 5,904 | 48,000 | 718 lb |
Winona County against the rest of Minnesota
Among the 87 Minnesota counties with data, Winona County is number 47 of 87 counting from the hardest. Across the whole country it is harder than 74% of counties.
Softest in Minnesota: Lake County at 1.3 gpg. Hardest: Traverse County at 42.6 gpg. Closest to Winona County: Dakota County (16.3), Wabasha County (16.4), Dodge County (16.2).