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Section IV <br />City Park Wet Detention Basins/Wetland <br />A. WET DETENTTON BASINS/WETLAND <br />1. Design Considerations <br />Two wet detention basins/wetlands will be constructed, on City of Long Lake parkland, at <br />the outlet of Storm Sewer 1 and 2 with a drainage area of 613 acres and 20 acres <br />respectively. The City of Long Lake currently maintains two existing unconnected <br />sedimentation basins in the park with a total area of approximately 0.39 acres. The existing <br />basins will be enlarged and deepened, to the extent feasible on the property, to improve <br />nutrient and sediment removal efficiencies. In addition, flow from the enlarged Storm Sewer <br />I basin will be diverted through a new pipe connection to the enlarged Storm Sewer 2 basin. <br />This will improve overall treatment efficiencies and to alleviate existing stagnation problems <br />in the Storm Sewer 2 basin. TTie basins are designed as a flow through system which diverts <br />typical flows through both basins. Extreme flows will discharge over an existing outlet <br />structure in Basin 1 as they do now. Final design plans are contained in Appendix A. <br />A permanent normal pool will be created at elevation 945.5 in basin 1 and at elevation 944.5 <br />in basin 2. The permanent pool is important for the same reasons presented for the County <br />Road No. 6 basin in Section II. <br />The basins are designed with a wetland fringe approximately 10 feet in width ranging from <br />elevation 945.5 - 944.5 and 944.5 - 943.5 around Basins 1 and 2 respectively. The wetland <br />fringe surrounds the open water and is constructed at a 10:1 slope. <br />N:>Ol t5>04.3»\OwifB.KPT-AES>I)«