Gravenhurst Water Hardness & Quality Report (2026)

The District Municipality of Muskoka supplies water to Gravenhurst through the Gravenhurst Water Treatment Plant. This facility draws raw water from an intake located on Lake Muskoka, near Brydon's Bay. The water is drawn from a depth of about 11.5 meters, roughly 1,000 meters from the shore. This surface water supply serves residents and businesses throughout the Town of Gravenhurst and surrounding areas within the Muskoka region of Ontario, Canada. Conventional treatment processes are employed, including coagulation, flocculation, sedimentation, filtration, and disinfection, ensuring the water meets drinking standards.

The Lake Muskoka water originates within the Canadian Shield, a region characterized by ancient Precambrian rock formations. Specifically, the bedrock consists of granitic gneiss and other metamorphic rocks. Unlike areas with significant limestone or dolomite deposits, the Canadian Shield geology is largely devoid of carbonate minerals. This lack of soluble rock, combined with thin glacial till and organic-rich soils, means that very little calcium and magnesium dissolve into the water, resulting in its naturally soft character. The extensive glacial scouring of the Shield further limits mineral leaching compared to other geological settings.

Gravenhurst's naturally soft water means residents typically won't encounter significant scale buildup in household plumbing, appliances like water heaters or dishwashers, or on fixtures. Soap will lather easily, requiring less product for cleaning tasks, and detergents will work more effectively. Because the water is so soft, a water softener is generally not needed and could even be detrimental. While corrosion is a consideration with soft water, routine monitoring by the utility has not indicated issues with lead or copper. Residents can enjoy a clear, clean supply that meets all provincial drinking water standards.