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Gem Lake News Page 3 of 6 <br /> <br /> <br />VLAWMO Lake Study <br /> <br />The Vadnais Lake Area Water Management <br />Organization (VLAWMO) was formed in 1983 to protect <br />the Vadnais Lake watershed area in northern Ramsey <br />County and a small portion of Anoka County. A joint <br />powers agreement was ratified by five cities and one <br />township within the boundaries of VLAWMO in order to <br />comply with the then new state law called the <br />Metropolitan Surface Water Management Act. The <br />purpose of the act, and through it the purpose of <br />VLAWMO, was to protect vital water resources that may <br />cross municipal boundaries. The municipalities within <br />this watershed include Gem Lake, Vadnais Heights, <br />White Bear Township, White Bear Lake, Lino Lakes and <br />North Oaks. <br /> <br />Other goals of VLAWMO include protecting groundwater <br />quality and recharge areas, providing public education, <br />protecting surface water quality, managing stormwater <br />and controlling flooding through the use of best <br />management practices. <br /> <br />VLAWMO conducts an annual water monitoring <br />summary for lakes and waterways within the watershed <br />district. The report is now available for 2022 and <br />includes some encouraging data regarding the health of <br />the waterbody of Gem Lake, as well as other nearby <br />waterbodies The water monitoring summary deals with <br />15 lakes, as well as Lambert Creek. Here are some <br />highlights that show the Watershed at a Glance, with <br />special emphasis on Gem Lake. Various data is <br />collected annually that give an overall view of the health <br />of lakes in the area. They include the Tropic State <br />Indexes, Phosphorus Totals, Secchi Disk readings and <br />Chloride Readings. Here is an overview of each: <br /> <br />Trophic State Indexes (TSI) of VLAWMO Lakes <br />The trophic status of a lake pertains to its nutrient levels, <br />transparency and chlorophyll. When a lake is <br />“oligotrophic” it has low nutrient levels and abundant <br />oxygen. It might be suitable for an unfiltered water <br />supply. The water is very clear. On the other end of the <br />scale is a lake that is “hypereutrophic.” That means it <br />has exceptionally high nutrients, causing dense algae. It <br />has a severe taste and odor and fish kills are possible. <br />The water would be very green. Gem Lake is right near <br />the middle of the scale, with only a few lakes in the area <br />coming in at the very green or hypereutrophic readings. <br /> <br /> <br /> <br />Average Total Phosphorus <br />Phosphorus is a naturally occurring nutrient and main <br />driver of algae growth. High phosphorus levels determine <br />whether the water looks like pea soup or an aquarium. <br />Excessive algae can produce foul smells and toxins <br />harmful to humans and pets. To prevent this, it is <br />important to keep sediment and nutrients on the <br />landscape and out of water bodies. Gem Lake’s <br />phosphorus level in one of the lowest in the region, <br />coming in at about 40 micrograms per liter. For <br />comparison purposes, West Goose Lake has a <br />phosphorus level of over 200 micrograms per liter. <br /> <br />Secchi Disk Readings <br />A Secchi disk is a 20 cm flat disk that is lowered into the <br />water until it can no longer be seen. The depth where the <br />disk disappears, called the “Secchi depth,” is a measure <br />of the transparency of the water. Transparency is the <br />most basic indicator to assess risks for most lake users, <br />and suggests potential issues downstream. Transparency <br />can be affected by pollutants or sediment draining into <br />the lake. Gem Lake’s readings are one of the best in the <br />area, with a Secchi reading of 2 meters. The least <br />transparent lake in the watershed had a reading of only <br />half a meter. <br /> <br />Chloride <br />Chloride is a common ingredient in salt de-icers and <br />home water softening. Chloride is a permanent pollutant <br />to water quality. It is toxic to aquatic life and interrupts <br />lake temperature. There are currently no waterbodies in <br />the watershed that are impaired by chloride levels. The <br />state standard says chloride levels should be less than <br />230 milligrams per liter. Gem Lake stands at about 20 <br />milligrams per liter. The highest reading in the watershed <br />is about 95 milligrams per liter. <br /> <br />Representatives from VLAWMO will be doing a <br />presentation of the annual report at the August Gem Lake <br />City Council meeting, which takes place on August 15 at <br />7:00 p.m. <br /> <br /> <br />Gem Lake Historical Avg TP/Chl A/ SDT <br />Year TP (µg/L) Chl A (µg/L) Secchi (m) <br />2017 32 16 1.5 <br />2018 36 15 1.8 <br />2019 33 11 1.8 <br />2020 35 14 2.4 <br />2021 38 13 2.4 <br />2022 39 8 2.4 <br /> <br />