Little Rock Water Hardness & Quality Report (2026)

Little Rock, Arkansas draws its municipal water supply from the Arkansas River, operated by Central Arkansas Water (CAW) at an intake located near the city in Pulaski County. The treated supply is processed at the Jack Wilson Water Treatment Plant on the north bank of the Arkansas River — the largest water treatment facility in Arkansas — using conventional coagulation, filtration, and disinfection. Central Arkansas Water serves both the city and surrounding communities in the metropolitan area from this single river source. Water hardness in Little Rock measures 200 mg/L — classified as hard, sitting precisely at the upper boundary of the moderately hard range.

Little Rock's hard water supply reflects the chemistry of the Arkansas River watershed. The river drains the Ouachita Mountains to the west — where Paleozoic sandstone and cherty limestone of the Ouachita fold belt contribute variable calcium loads — before crossing into the Gulf Coastal Plain underlain by Cretaceous and Tertiary marl, chalk, and calcareous sediment. Agricultural drainage from the flat Arkansas River valley and the calcium-rich soils of the surrounding plain contribute significantly to the river's bicarbonate and calcium content, consistently pushing supply into the hard category after treatment.

At 200 mg/L, Little Rock residents face notable scale build-up in daily household use. White calcium deposits accumulate on faucet aerators, showerheads, and inside kettles over several weeks — monthly descaling is a sensible maintenance routine. Water heaters experience moderate to significant element scaling over time; professional annual servicing or DIY descaling is recommended. Dishwashers should be run with rinse-aid to prevent persistent cloudy film on glassware. A whole-house scale inhibitor offers meaningful protection for appliances and is worth considering in households with newer, scale-sensitive water heaters or washing machines.