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<br />stormwater Project Plan <br /> <br />A. Project Desaiption <br />The proposed project focuses on developing best management practices for Centerville Lake as a <br />part of the redevelopment of Centerville's downtown. Stormwater runoff is conveyed by an <br />existing storm sewer system directly to Centerville Lake with no treatment as shown on the <br />attached figure. The green infrastructure aspect of the project includes a new storm sewer <br />system to convey downtown runoff to a proposed holding pond to be utilized for irrigation of an <br />existing park facility. <br /> <br />Centerville Lake is 303( d) listed by the MPCA as impaired for aquatic recreation due to total <br />phosphorus loads. Rice Creek Watershed District (RCWD) notes that improvement of the lake for <br />water-based recreation is one of the primary goals of the watershed. RCWD is currently in the <br />process of a completing a TMDL study for Centerville Lake. Retrofitting best management <br />practices with the proposed downtown nedevelopment aligns with the goal of improving the <br />water quality of Centerville Lake. The City wishes to leverage Green Infrastructure Funds along <br />with its stormwater utility, RCWD Urban Stormwater Remediation Cost-Share Program grant, and <br />Board of Soil and Water Resources Oean Water Legacy Grant for the first phase of the <br />stormwater Improvements. <br /> <br />B. Project Service Area <br />A key component of this project is installation of storm sewer and construction of a holding pond <br />and irrigation system to meet Rice Creek Watershed District (RCWD) requirements. The project <br />serves an approXimately 22 acre drainage area (13.8 acres of Impervious). Specifically, the <br />features have been designed to capture 2.8 inches of runoff from the impervious surfaces. There <br />is a significant decrease in the 2, 10 and lOO-year proposed discharge rates from existing <br />conditions. Table 1 lists the existing and proposed discharge rates to Peltier Lake and Oearwater <br />Creek from the project area. <br /> <br />Scenario <br /> <br /> <br />2- ear <br />Existin 14.7 <br />Pro sed 4.3 <br /> <br />C. Project Location, BMPs, ConsbUctlon Costs, Operations and Maintenance, <br />Equipment Costs <br /> <br />The project is located in the City of Centerville in Anoka County, specifically within the downtown <br />area roughly bounded by Main Street to the north Goiffon Road to the east, bordering Heritage <br />Street to the south and the property east of Progress Road as shown on the attached figure. A <br />combination of BMPs is proposed including a new storm sewer system to convey runoff to the <br />proposed holding pond, water re-use system, pervious pavement, rain gardens/bioretention. The <br />holding pond allows for sedimentation prior to being utilized by the water re-use system for <br />Irrigation of an adjacent park area. <br /> <br />The total estimated construction cost for the stormwater improvements is $852,863 as shown on <br />the attached construction cost estimate. The City is requesting PFA funding for $549.913 of the <br />total cost. Routine maintenance of the holding pond and water re-use system is to be completed <br />by the City. Routine maintenance of the local BMPs within the downtown redevelopment is also <br />to be completed by the Oty, except with small BMPs that may be proposed with the construction <br />of private properties. (These private BMPs have not been included in the cost estimate). Holding <br />ponds of this type have an estimated life cycle of 50-75 years. E5tIl......,IIIlnulIIMaIllh.fllllCie <br />