Redding Water Hardness & Quality Report (2026)

Redding, California, the Shasta County seat at the northern end of the Sacramento Valley, draws its municipal water supply from the Sacramento River via the City of Redding Electric Utility Department water operations, with a Sacramento River intake at the Keswick–Anderson stretch north of Redding in Shasta County. The Sacramento River at Redding is impounded by Shasta Dam (Shasta Lake) — the primary storage reservoir — which drains the upper Sacramento Valley watershed including the Trinity Alps and Shasta and Trinity Counties. Water hardness measures 186 mg/L — classified as hard, notably higher than expected for a Northern California river source.

Redding's surprisingly hard supply reflects the complex upper Sacramento watershed geology and possibly significant Trinity River Diversion influence. Shasta Lake impounds the McCloud River (from the Modoc Plateau — Columbia River Basalt and Pliocene volcanic terrain), the Pit River (from the Modoc Plateau — Tertiary basalt and calcareous marine formations of the Modoc Plateau calcareous terrain — a notably more calcium-rich watershed than expected), and the Sacramento River headwaters (Mt. Shasta volcanic terrain). The Pit River drains particularly calcareous Modoc Plateau bedrock — Cretaceous and Paleocene calcareous marine formations of the intermontane basin — contributing significant dissolved calcium. The Trinity River Diversion also carries Klamath Mountains serpentinite and calcareous schist contribution.

At 186 mg/L, Redding residents face regular hard water challenges. Scale deposits form on faucet aerators, showerheads, shower glass, and tile 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. City of Redding consistently delivers water meeting all California SWRCB and EPA Safe Drinking Water Act requirements.