CCP 09-27-2004 - Laserfiche WebLink

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. . . 7.8 Wetlands No natural wetland system will be directly impacted by the proj eel. Part of the storm water runoff from Lexington A venue will, however, be discharged to an existing stormwater ponds north and south of Victoria along the east side of Lexington Avenue. Although rrummade, natural wetland vegetation has been established in this basin. Expansion ofthe existing pond to accommodate the increased volume of storm water will be provided to treat nmoff from additional pavement area and sidewalk along the east side of Lexington. Excavation and grading modifications to the pond will impact approximately 0.24- acre pcrimeter pond area. Restoration of graded areas will reestablish a healthy perimcter plant community. 7.9 Floodplains According to the FEMAJFIRM Floodplain maps for the project corridor, lOO-year floodplains are identified around Karth Lakc. No permanent structure or earthwork will be done within the floodplain areas. Hydrologic impacts of minor additions to pavement area and construction of a sidewalk on the east side of Lexington may occur but are considered negligible as the overall drainage area tributary to Karth Lake is essentially the same. Additional pond capacity will he added to an existing pond area south of Victoria along thc east side of Lexington Avenue to buffer hydrologic events and treat additional runoff. 7.10 Water Resources and Water Quality Thc segment of Lexington Avenue forms the border betwecn the Rice Creek Watershed District and the Grass Lake Watershed Management Organization (WMO). Under existing conditions, the northern one third of the project flows northward and carried easterly via storm sewer constructed along Highway 96, discharging into an existing treatment pond area within the Snail Lake Regional Park area. The southern half of the project discharges, in part directly to Karth Lake, and also to two existing pond areas north and south of Victoria Street along the east side of Lexington. Proposed rcconstruction of Lexington A venue will utilize the existing trunk stonn sewer systcm. Drainage to the north as cited above was assumed in the design for water treatment along the reconstructcd portion of Highway 96 in accordance with the requirements of the Grass Lakc WMO, as addressed in the City of Shore view Surface Water Quality Management Plan (1990). The south two thirds of the Lexington project will have to meet both Grass Lake WMO and Rice Creek Watershed District requirements -- as initial roadway discharge is to existing pond areas within the former, but ultimate overflow [rom those basins is to the latter (Karth Lake). The Lexington Avenue project will also be subject to the provisions oflhe Minncsota Pollution Control Agency (MPCA). Erosion control measurcs as suggested by the Minnesota Pollution Control Agency's Best Management Practices (BMPs), and as required by the NPDES Pcrmits and the local govcmmental units would be installed to mitigate construction activity impacts. These measures ,vill be specificd in the contract documents and on the dcsign plans, as applicable. Proposed Storm 'Vater System Stonn sewer upgrades will be constl1lctcd as pmi of this projecl. The anginal trunk system will \\'l::nnc 'l~. lUn~!. 6