Windsor Water Hardness & Quality Report (2026)

Windsor's drinking water is managed by Enwin Utilities (formerly Windsor Utilities Commission), drawing from the Detroit River via the Windsor Water Treatment Plant on the riverfront. Water undergoes conventional coagulation, sedimentation, filtration, UV disinfection, and chloramination, fully complying with the Guidelines for Canadian Drinking Water Quality (GCDWQ). Hardness measures 145 mg/L (8.5 gpg) — classified as hard by Health Canada, reflecting the moderately mineral-rich Great Lakes water chemistry that characterises this borderland supply.

The Detroit River connects Lake St. Clair to Lake Erie, carrying water that has accumulated dissolved minerals across the Great Lakes watershed — particularly from Silurian dolomite and Devonian limestone formations in southern Ontario and northern Michigan. As inflow from these carbonate-rich geological sequences enters the upper Great Lakes, it builds a consistent mineral load that persists through the lake chain to Windsor's river intake. Lake Erie's relatively shallow depth and agricultural runoff from Essex County's productive farmland can slightly elevate mineral concentrations during summer months.

At 145 mg/L, Windsor homeowners notice regular scale build-up on kettle heating elements, tap aerators, and inside hot water tanks — descaling every four to six weeks is typical. Hot water tank efficiency declines as scale coats electric heating elements; Enwin Utilities recommends annual tank inspection and flushing. A whole-home water softener significantly reduces appliance wear, bathroom scale deposits, and detergent consumption — a worthwhile investment given Windsor's consistently hard water, especially for households with new high-efficiency water heaters or dishwashers.