Lake health is not defined by a single measurement. Water quality, aquatic plants and shoreline conditions are monitored over a five-year cycle to show how the lake and its watershed are changing.

Lake Scugog is monitored as part of Kawartha Conservation’s Lake Health Monitoring Program. The program brings together information from three areas: water quality and vertical lake profiling, aquatic plants, and shoreline condition. Staff monitor nutrients and other water-quality indicators, measure temperature and dissolved oxygen from the surface to the lake bottom, survey aquatic plant species and abundance, and assess natural and altered shoreline areas. Looking at these indicators together provides a more complete understanding of the lake, helps track changes over time, and informs decisions that support its long-term health.

The current StoryMap presents the results of 2025 monitoring conducted at six locations on Lake Scugog and seven stream and river locations within the surrounding watershed. It identifies phosphorus as the primary water-quality concern in the lake and notes elevated phosphorus levels in most tributaries. Aquatic plant surveys found plants across much of the lake, but also revealed a limited presence of sensitive species and widespread invasive plants, including Starry Stonewort and Eurasian Watermilfoil. Shoreline monitoring found a moderate loss of natural plant cover since 2002, along with relatively low amounts of woody structure and overhanging vegetation. Together, these findings identify several areas of concern and provide an important baseline for tracking how Lake Scugog changes over time.