Bay City Water Hardness & Quality Report (2026)

Bay City, Michigan, the Bay County seat — a major east central Michigan Saginaw Bay community (Bay City is the Bay County seat and one of the significant east Michigan cities on Saginaw Bay — historically a major lumber and shipbuilding city on the Saginaw River during Michigan's 19th century timber era), home of Wenonah Park (a historic park on the Saginaw River — one of the landmark public spaces in Bay City), a diverse Bay County community with a significant Polish-American, German-American, and declining but historically significant Native American population, and a community in the Tri-Cities area (Bay City, Saginaw, and Midland form the Tri-Cities of east central Michigan) — draws its municipal water supply from the Saginaw River via the City of Bay City Water Division. Water hardness in Bay City measures 123.5 mg/L — classified as moderately hard.

Bay City's moderate hardness reflects the east central Michigan Saginaw River watershed's calcareous Paleozoic carbonate geology. The Saginaw River (Tittabawassee River) at Bay City–Bay County draws from: the Devonian–Mississippian Michigan Basin limestone and dolomite (highly calcareous marine carbonate of the Michigan Paleozoic Basin — the Traverse and Dundee Limestone formations); and the Pennsylvanian Saginaw Formation (calcareous-moderate). City of Bay City treatment produces the moderate 123.5 mg/L.

At 123.5 mg/L, Bay City residents encounter moderate scale accumulation. Monthly cleaning with citric acid solution is recommended. City of Bay City Water Division consistently delivers water meeting all Michigan DEQ and EPA Safe Drinking Water Act requirements.