Laserfiche WebLink
<br />I <br />.. CONCLUSION <br /> We have contacted Mr. Tom Hovi, Minnesota Department of Natural Resources (DNR), <br />I to check if any low areas in this drainage area are listed as protected <br />I wetlands. The maps do not indicate any protected wetlands, therefore a permit <br /> is not required from the DNR. Mr. Joe Vanta with the U.S. Army Corps of <br />I Engineers will review the plans to determine if a permit is required from the <br /> U.S. Army Corps of Engineers. <br />I <br />I The fOllowing items should be completed to provide an overflow from the wetland <br /> preservation area to pond A-7a: <br />I 1) Install baffled weir in wetland preservation area with top of baffled <br /> weir at elevation 970.5. Refer to page 4 of the plans for a detail of <br /> baffled weir in wetland preservation area. <br />I 2) Install 24" reinforced concrete storm sewer from wetland preservation <br /> area to pond A-7a. Refer to page 2 of the plans for the plan and <br />.. profile of the storm sewer. <br /> 3) Install Class IV rip rap at outlet of 24" RCP as shown on pages 2 and <br /> 3 of the plans. <br />I 4) Install baffled weir at Northwest corner of pond A-7a with the top of <br /> baffled weir at elevation 946.1. Refer to page 4 of the plans for <br />I detail of baffled weir in pond A-7a. <br /> 5) Grade area from pond to baffled weir to an elevation of 944.7. <br />I 6) Restore turf in areas disturbed and provide erosion control as shown <br /> and as required by Watershed. <br />I These items must be completed when the drainage area is developed: <br />I 1) Provide a 15 inch reinforced concrete pipe outlet from pond A-7a. <br /> Install an orifice plate with a 13 inch diameter opening in the <br /> upstream end of the pipe. This will provide a 4.8 cfs maximum out <br />I flow from the pond. The invert of the 15" RCP should be 945.3, with a <br /> slope of .56% to the west. <br /> 2) Grade pond A-7a to contain 1.95 ac ft. of storage. The pond will rise <br />~. to an elevation of 947.3. <br /> 3) Provide a 10 foot wide emergency overflow channel at elevation 947.3 <br /> over the 15" RCP outl et. <br />I <br />I <br />