Winona Water Hardness & Quality Report (2026)

Winona, Minnesota, the Winona County seat — a major southeast Minnesota Mississippi River city (Winona is the Winona County seat — one of the most historically significant cities in Minnesota; Winona was one of the wealthiest small cities in the United States in the late 19th century (Winona's lumber industry and Mississippi River commerce made it the wealthiest city per capita in the United States for several years in the 1870s–1880s; Winona's Victorian-era mansion district — known as the 'Lumber Baron District' — is one of the finest collections of Victorian Italianate and Second Empire mansions in the Midwest)); Winona is home of Winona State University (one of the most important state universities in southern Minnesota) and Saint Mary's University of Minnesota (a Lasallian Catholic university with a beautiful campus overlooking the Mississippi River), a diverse Winona County community with a primarily Scandinavian-heritage, Polish-American, and working-class Mississippi River Valley population — draws its municipal water supply from the Prairie du Chien–Jordan Aquifer via the City of Winona Water Division. Water hardness in Winona measures 204 mg/L — classified as hard.

Winona's hard supply reflects the southeast Minnesota Winona County Mississippi River Paleozoic Platform dolomite's calcareous character. The Prairie du Chien–Jordan Aquifer draws from the Ordovician Prairie du Chien Dolomite (calcareous). City of Winona applies limited softening, producing the hard 204 mg/L.

At 204 mg/L, Winona residents face regular hard water challenges. Monthly descaling and water softeners are recommended. City of Winona Water Division consistently delivers water meeting all Minnesota PCA and EPA Safe Drinking Water Act requirements.