Laserfiche WebLink
_ . , PC Exhibit D <br /> • = BO!-TON 8; M �N K , I NC� <br /> � Consulting Engineers & Surveyors <br /> " 2638 Shadow Lane, Suite 200•Chaska, MN 55318-1172 <br /> Phone(952)448-8838• Fax(952)448-8805 <br /> www.bolton-menk.com <br /> October 8, 2012 , <br /> City of Orono <br /> Attn: Melanie Curtis <br /> PO Box 66 <br /> Orono,MN 55323 <br /> RE: Preliminary Plat Application 12-3579 <br /> John Lein Plat-2700 Sixth Avenue North <br /> Engineering Review#1 <br /> Dear Melanie: • <br /> As requested,we have completed an engineering review of the documents submitted for the above� � <br /> referenced project. Our current review is based on the following submittal items: <br /> � • Subdivision Application; dated 9/19/12 � <br /> • Preliminary Plat prepared by Gronberg&Associates;dated 9/17/2012 <br /> • Preliminary Road Plan&Profile prepazed by Gronberg&Associates;dated 9/17/2012 <br /> • WCA Notice of Decision for Wetland Boundary; dated 10/13/12 <br /> • Conservation Design Report prepared by Svoboda Ecological Resources; dated 9/18/2012 <br /> • Vegetation Management Plan prepared by Svoboda Ecological Resources; dated 9/18/2012 <br /> • Drainage Calculations prepared by Gronberg&Associates; dated 9/18/2012 <br /> � Drainage Area Map prepared by Gronberg&Associates; dated 9/17/2012 <br /> - We offer the following observations, comments, and recommendations for your consideration: <br /> 1. The grading around the proposed pond and existing intermittent creek needs to be better defined. <br /> - The 988 contour west•of the pond is possibly mislabeled as 990, and if the-creek is to be rerouted <br /> around the pond,additional contours, spot elevations,and drainage arrows should be added to better <br /> delineate what is proposed. <br /> 2. A�Stormwater Pollution Prevention Plan(SWPPP)will need to be submitted as part of the Final <br /> Plans. The SWPPP should include additional siltfence along the internuttent creek as necessary, <br /> riprap on the downstream end of all culverts for energy dissipation,erosion control blanket and ditch <br /> checks on the swale from the road to the pond, and a rock construction entrance. <br /> 3. Drainage calculations for the proposed stormwater pond meet City requirements. Proposed runoff <br /> rates will be restricted to less than existing runoff rates. <br /> 4. Drainage calculations must be submitted as part of the Final Plans to confirm sizing of all culverts, <br /> including the existing culvert under the driveway for Lot 3. <br /> 5. As part of the Final Plans,Drainage and Utility easements must be placed over the wefland,wetland <br /> buffer, stormwater pond,intermittent creek, and all ditching and culverts directing runoff to the pond <br /> or wetland. The easements should be shown on the Final Plat and Final Street,Utility, and Grading <br /> Plans. <br />