WATERSHED WATCH PATTERSON LAKE LOCATION: Patterson Lake is located in the newly amalgamated Township of Lanark Highlands, in Lanark County, north of McDonalds Corners. SIZE / DEPTH: Maximum Depth - 15.8 metres Perimetre - 11.27 kilometres QUALITY: In general the water quality in Patterson Lake is good. The average Secchi Disk reading is 5.4 metres indicating Patterson Lake as an unenriched (few nutrients) or oligotrophic lake. Related to water quality is the amount of nutrients entering the lake, in particular phosphorus. The Provincial Water Quality Objective for Total Phosphorus for Patterson Lake is 20 micrograms per litre. The mean for the euphotic zone (penetration of light) for 2001 is 8.8 micrograms per litre indicating an unenriched lake. The mean for the sample taken one metre off the bottom is 16.3 micrograms per litre indicating a moderately enriched (some nutrients) or mesotrophic lake. Chlorophyll a is a measure of the algal density in the lake. The average chlorophyll a densities for the sampling station was 2.94 micrograms per litre indicating a moderate algal density for Patterson Lake in 2001. SURROUNDING LAND: Cottages - 63 (as of 1980) Permanent Residences - 1 (as of 1980) Vacant Lots - 22 (as of 1980) ACCESS: Patterson Lake has no public access. FISH: Smallmouth Bass, Bluegill, Largemouth Bass, Yellow Perch, Northern Pike, Rock Bass, Common White Sucker, Pumpkin seed (Sunfish) If you require additional information, please contact info@mvc.on.ca Tel: (613) 259-2421.