Johns Creek Water Hardness & Quality Report (2026)

Johns Creek, Georgia, in northern Fulton County along the Chattahoochee River near the Forsyth County border, draws its municipal water supply from the Chattahoochee River via the City of Johns Creek Utilities Division and through connections to the Fulton County Department of Public Works Water infrastructure — drawing treated Chattahoochee River water from the northern Fulton County water system. Water hardness in Johns Creek measures 84.5 mg/L — classified as moderately soft.

Johns Creek's softer reading compared to Roswell (124.5 mg/L) — both on the Chattahoochee River in north Fulton County — reflects Johns Creek's more northerly position on the Chattahoochee, closer to the river's Blue Ridge mountain origin. The Chattahoochee River enters the northern Fulton County–Forsyth County zone close to its source in the Georgia Blue Ridge (Precambrian quartzite and mica schist of the Tallulah Falls Formation and Cartoogechaye Terrane). At the Johns Creek reach, the river has accumulated less mineral content from Georgia Piedmont interaction than at the Roswell reach further south, maintaining a softer, mountain-water character. The 84.5 mg/L reading reflects the transition from Blue Ridge soft water to Piedmont moderate hardness along the Chattahoochee corridor.

With hardness at 84.5 mg/L, Johns Creek residents experience minimal to moderate scale challenges. Faucet aerators and showerheads develop deposits slowly — bi-monthly cleaning with citric acid solution is sufficient. Dishwashers produce clean glassware. City of Johns Creek Utilities and Fulton County Water consistently deliver water meeting all Georgia EPD and EPA Safe Drinking Water Act requirements.