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3 <br /> <br />Soils <br /> <br />The Natural Resource Conservation Service Web Soil Survey notes the following soil <br />types on the project site: <br /> <br />Glencoe loam: Hydrologic group B/D, very poorly drained, hydric. <br /> <br />Nessel fine sandy loam: Hydrologic group B, moderately well drained, not hydric. <br /> <br />Webster loam: Hydrologic group B/D, poorly drained, hydric. <br /> <br />Hayden fine sandy loam: Hydrologic group B, well drained, not hydric. <br /> <br />Nowen sandy loam: Hydrologic group B/D, poorly drained, hydric. <br /> <br />The majority of the project area has poorly drained soils with high clay content. Due to <br />the high clay content and the site’s inclusion in the Drinking Water Supply Management <br />Area, infiltration of stormwater is not feasible. <br /> <br />Stormwater Management <br /> <br />A stormwater management plan has been submitted and is being reviewed by the City <br />Engineer. The following summary review is based upon the existing and proposed <br />drainage figures and calculations, and the written stormwater management narrative <br />included with the Stormwater Pollution Prevention Plan (SWPPP). <br /> <br />Existing Conditions <br /> <br />Stormwater on the site currently sheet flows from grass areas and parking lots to filter <br />basins in the south of the site. From there the water heads into the City storm sewer <br />system near Otter Lake Road before heading to a regional stormwater pond south of the <br />site. <br /> <br />Proposed Conditions <br /> <br />Under the proposed conditions, there will be 2.06 acres of new impervious surface. <br /> <br />A wet sedimentation pond will be constructed south of the proposed storage area to <br />accommodate stormwater runoff that will sheet flow from the additional impervious <br />surface. A drainage swale running along the south of the existing storage area will carry <br />water from the existing storage area west to the new pond. The pond will also be sized to <br />accommodate water that was managed by a raingarden that was filled in during the <br />unpermitted grading activity. Overflow from the pond will be routed to the City storm <br />sewer system near Otter Lake Road before heading to the regional stormwater pond south <br />of the site. <br />