Laserfiche WebLink
100-Year 100-Year <br />Outlet Pipe HWL HWL <br />Size (658W) (659W) Estimated Cost <br />1 Existing 862.1 860.4 N/A <br />Existing + 15" 861.8 861.2 $15,290 <br />Existing + 18" 861.7 861.3 $18,755 <br />Existing + 24" 861.6 861.4 $29,040 <br />Tables 9 through 11 include the individual costs for this alternative. <br />As mentioned above, it is our understanding that any work proposed below an elevation <br />of 860 will need the approval of the DNR. This alternative will not have any effect <br />below an elevation of 860 and is not anticipated to need the approval of the DNR. <br />Removing the weir structure and constructing a culvert under TH 47 will require <br />MnIDOT's approval. <br />Alternative 3 <br />Alternative 3 will include removing the existing weir structure and constructing an <br />additional outlet from DNR Wetland 658W under TH 47. The proposed additional outlet <br />would be at an elevation of 859.0, one foot lower than the existing outlet. It was assumed <br />the additional pipe would have to be jacked under TH 47. <br />Two different sized additional outlet pipes were analyzed. The following table <br />summarizes the 100-year HWL's for DNR Wetlands 658W and 659W and the estimated <br />costs to construct each outlet pipe: <br />100-Year 100-Year <br />HWL HWL <br />Outlet Pipe Size (658W) (659W) Estimated Cost <br />Existing 862.1 860.4 N/A <br />Existing + lower 18" 861.6 861.3 $18,755 <br />Existing + lower 24" 861.6 861.5 $29,040 <br />Tables 12 and 13 include the individual costs for this alternative. <br />As mentioned above, it is our understanding that any work proposed below an elevation <br />of 860 will need the approval of the DNR. This alternative has work proposed below an <br />elevation of 860 and will need the approval of the DNR. Removing -the weir structure <br />and constructing a culvert under Trunk Highway 47 will require MnIDOT's approval. <br />