CCP 11-29-1999 - Laserfiche WebLink

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I I. I I I I I I I I. I I I I I I I. I I Proposed Storm Draina!!:e Improvements A. Storm Sewer The proposed improvements include storm sewer construction in all roadways scheduled for reconstruction. Storm sewer improvements include catch basins along curb lines, trunk sewer and outlets into the proposed Regional Ponds described below. Some existing storm sewer is located in Fernwood Court and Fernwood Street however the report has assumed that these facilities will be replaced. The existing storm sewer condition and location will be field surveyed as a part of final design. If the sewer is found to be in a usable location, of good condition and adequate capacity, the plans will provide for the reuse of the existing storm sewer. The proposed storm sewer improvements are based upon collecting street runoff and transporting that runoff to the two regional ponds and the Fernwood Court channel area. The two regional ponds would drain into the existing ditch system west of Hamline Avenue which drains to Lake Johanna. The Fernwood Court Channel would drain into Lake Josephine. There are two properties located within the project area which will likely require area drains and connection to the storm sewer in order to provide adequate lot drainage. Final location of area drains and lot grading will be coordinated with the affected property owners during the final design of the project. B. Regional Storm Water Ponds This report has evaluated two possible sites for regional storm water ponds. The general topography of the neighborhood falls steeply from Lexington A venue to approximately Fernwood street then falls very slowly to the west towards an existing wetland located between Ingerson Road and Tiller Lane. Several undrained low areas exist along Ingerson Road which routinely flood into the adjacent residential lawns. The southern portion of the neighborhood drains directly to Lake Josephine through storm sewer and overland flow. The western and northern portion of the neighborhood drains directly to the wetland described above. There are two logical sites for constructing storm water quality ponds which will help trap sediments and pollutants carried by storm water before that runoff reaches Lake Josephine and Lake Johanna. Both ponds included in the report have been preliminarily sized to meet the criteria set by the National Urban Runoff Program (NURP) which results in the removal of 60%-70% of phosphorus and other pollutants typically found in storm water runoff. The Rice Creek Watershed criteria for pond construction in new developments is consistent with the NURP standards. The construction of both ponds would require coordination with MnDOT and the Rice Creek Watershed. Representatives from the Rice Creek Watershed have indicated that up to $100,000.00 in funding may be available to the City for the construction of the ponds. Both proposed sites are 4