COMFORT LAKE FOREST LAKE Watershed District 2006 Water Monitoring Report

The work plan for 2006 included monitoring of ten lakes (Forest Lake 1st, 2nd, and 3rd Basins and Bone Lake monitored by Randy Anhorn at Metropolitan Council Environmental Services and Sylvan/Halfbreed lake to be monitored by Curt Sparks {lake resident and Minnesota Pollution Control Agency Citizen Lake Monitoring Program volunteer}). All lakes were monitored biweekly from April through October except School and Birch Lake (monitored monthly from April through October), and Sylvan/Halfbreed Lake (monitored for secchi transparency only on an available volunteer basis). All lakes were monitored by collecting Secchi transparencies, temperature, and dissolved oxygen profiles. Secchi transparencies are used for general comparisons of water quality across the watershed and for monitoring general water quality trends in a given lake from year to year. Temperature and dissolved oxygen profiles provide information on the in-lake dynamics and how each lake may be functioning each year. All ten lakes had 2-meter surface composite water quality samples taken for analysis of total phosphorus, total Kjeldahl nitrogen, and chlorophyll-a concentrations. All lakes except for School, Birch, and Sylvan/Halfbreed Lake had subsurface hypolimnion samples collected using a Van Dorn horizontal water quality sampler. The hypolimnion samples were analyzed for total phosphorus, dissolved ortho-phosphate, and total iron. Bone Lake and Forest 1st, 2nd, and 3rd Basins also had 2- meter surface composite water quality samples taken that included the analysis of total chloride ions and dissolved ortho-phosphate, and metalimnion samples of total phosphorus, total Kjeldahl nitrogen,, and dissolved ortho-phosphate. Zooplankton tows were conducted using a Wisconsin style 80-μm plankton net for analysis on Bone Lake, Shields Lake, and Forest 1st, 2nd, and 3rd Basins.