Broken Arrow Water Hardness & Quality Report (2026)

Broken Arrow, Oklahoma — the largest suburb of Tulsa and one of Oklahoma's fastest-growing cities — draws its municipal water supply through the City of Broken Arrow Utilities, sourcing from the Tulsa Metropolitan Utility Authority (TMUA) regional system, which delivers treated water from the Spavinaw Lake system — impoundments on Spavinaw Creek (Grand Lake watershed) in Cherokee County in northeastern Oklahoma's Ozark Plateau, supplemented by the Oologah Lake system on the Verdigris River. Water is treated at the A.B. Jewell Water Treatment Plant in Tulsa before distribution to Broken Arrow via the Tulsa metro distribution network. Water hardness measures 199 mg/L — classified as hard.

Broken Arrow's hard supply reflects the Ozark Plateau carbonate geology of the Spavinaw and Verdigris watershed systems in northeastern Oklahoma. Spavinaw Creek drains the Ozark Plateau — underlain by the Ordovician Gasconade Dolomite, Devonian Hunton Group limestone and dolomite, and Mississippian Boone Formation chert and limestone — ancient marine carbonate formations of the Mid-Continent platform. These Ozark Plateau carbonate rocks are highly soluble, especially the Hunton Group dolomite and Boone chert-bearing limestone, which dissolve significant calcium bicarbonate into Spavinaw Creek drainage. The Oologah Lake (Verdigris) supplement draws from the Pennsylvanian and Mississippian calcareous formations of northeastern Oklahoma, contributing additional mineral loading.

At 199 mg/L, Broken Arrow residents face regular hard water challenges. Scale deposits form on faucet aerators, showerheads, and inside appliances within weeks — monthly descaling with citric acid solution is standard maintenance. Dishwashers require rinse-aid for acceptable glassware results, and water heaters benefit from annual inspection for element scale. City of Broken Arrow Utilities and TMUA consistently deliver water meeting all Oklahoma DEQ and EPA Safe Drinking Water Act requirements.