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Technical Findings <br />Since monitoring information for Bennett was available from Ramsey County, Bennett was <br />visited oniy once on Ju�y 18, 2Q01 as part of the Natural Resources Inventory. <br />Water Quality <br />Water quality data for Bennett Lake extends as far back as 1984. Data collected between May <br />and September of 2001 by Ramsey County staff is presented in Appendix A, Table 2 and shows <br />that the mean secchi depth was 1.11 feet, a reiatively low reading even for an urban lake in this <br />region. The growing season mean concentration of total phosphorus for Bennett was 140 ug/1, <br />putting it Eoward the poorer quality end of the D category (69-152 u�/1) for the lake water quality <br />report card developed by the Met Council. These data indicate that Bennett Lake is hyper- <br />eutrophic, meaning it is very nutrient enriched and can be expected to show problerns with <br />severe algal blooms for most of the rccreational season. <br />Aquatic Vegetation Survey <br />A one-time reconnaissance level survey of aquatic vegetation in Bennett Lake was carried out on <br />7uly l8, 2Q01 as part of th�s project. Following are the conclusions of the survey: <br />• There was evidence of a curly-leaf pondweed infestation in the ]ake but no evidence <br />of eurasian milfoil. The survey was conducted well after the peak �rowti� of curly- <br />leaf pondweed usually occurs, so t�is exotic might bc much more dominant earlier in <br />the summer. <br />• The maximum depth of submergent aquatic weed growth at the time of the survcy <br />appcared to be about 3-4 feet. This is 3ikely a reflection of the limzted light <br />penetration through the water column causcd by al�al blooms �rowing in response to <br />high nutrient concentrations in the lake. <br />The diversity of native macrophyie species observed was low, �vith only coontail and <br />Canadian waterweed observed in any abundance. <br />• There were significant growths of fiiamentous algae floatintr in rr�ats on top of the <br />water in many inshore locations. This is symptomatic of a very nutrient enriched <br />system. <br />Ciry of Roseville 49 <br />Parks �Vat�tral Resoeerce Nfa�iagernetit <br />