Lake Water Quality 2006 Report - Lakefield Herald

Ontario’s Natural Resources and Values Information System (NRVIS) database(MNR, 2002) and the Water Resources and Information Project (WRIP) (MNR,2006) were utilized to acquire land class information and watershed delineations.These data were then overlaid and analysed using ArcMap ® to determine watershedboundaries and the land uses within them.It was found that the Kawartha Lakes watershed (8,990 km 2 ) consists of 31quaternary watersheds. As seen in Figure 2.1, of the possible 28 land uses identifiedby the NRVIS data, the Kawartha Lakes watershed is represented by 21 differentland uses. Interestingly, the chain of lakes running west/east through the middle ofthe watershed (Trent-Severn Waterway) runs parallel with a transition zone betweenforested Canadian Shield (metamorphosed limestone and/or granite) catchments tothe north and agricultural glacial till catchments to the south. This transition zoneincludes a significant limestone alvar plain that runs through the Kawartha Lakeswatershed.Previous models of lake phosphorus concentrations and catchment-related phosphorusdynamics would be problematic if applied to the Kawartha Lakes area. This is due tothe unique situation of having lakes located between two extreme geological featurescombined with unusually shallow lake systems. Most have artificially high water levelsdue to dam creation for the Trent-Severn Waterway; this causes the historicalfloodplain to be inundated with water, forming large areas of shallow water wheremacrophytes (aquatic plants) can proliferate. The landscape to the south of theKawartha Lakes is dominated by cultivated land with glacial till, while the area to thenorth is dominated by forested areas and impermeable bedrock.35