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located where wetland does not currently exist, but where adequate hydrology is <br />available. There are also several areas of reed canary -dominated wetland that could be <br />improved for public value credit though re-establishment of native wetland communities. <br />Any wetland improvements in this area could be designed to also improve Blanding' s <br />turtle habitat. <br />The following are proposed to mitigate impacts associated with the stormwater outfall to <br />the Mississippi River: <br />Reduce Frequency of Stormwater Discharge, Lower Magnitude of Peak Flow Rates: The <br />RTC project incorporates a variety of strategies to lower increases in stormwater rate and <br />volume. While all stormwater conveyance features are designed to accommodate the <br />100-year runoff event without taking infiltration into consideration, on -site retention and <br />infiltration can be incorporated at multiple scales into the RTC during the detailed design <br />phase for smaller storm retention. Peak flow rates for the 100-year, 24-hour runoff and <br />100-year, 10-day snowmelt events are 25.1 cfs and 25.3 cfs respectively. <br />Oversize Culvert and Reduced Slope at Outfall: The last section of culvert will be <br />enlarged from 21-inches to 36-inches and include an apron and rip -rap to lower velocities <br />and dissipate the energy at the discharge point. This will minimize the potential for scour <br />and erosion. <br />Directional Boring to Install Culvert: If possible, the culvert will be placed within the <br />river bank by directional boring rather than an open cut. This will reduce the need to <br />remove shoreline vegetation and will minimize the area of disturbance. Erosion control <br />measures will be implemented where soil is disturbed. All disturbed areas will be <br />replanted to native trees, shrubs, grasses and forbs and if appropriate, a temporary cover <br />crop will be established. <br />12-9 <br />