Laserfiche WebLink
W <br />Orto G Bonestroo, PE. <br />Bonestroo <br />IE <br />Jooseph rt tC AnA�ikP PE <br />Rosene <br />rg.PE PE <br />Bradford A Turner. <br />RK hard E Turner. PE <br />MEN <br />Anderlik � <br />PE <br />Jame' C Con.ok, <br />Glenn R Cook. PE <br />Associates <br />Thomas E. Noyes. PE <br />Robert G Schunrcht, PE <br />Marvin L Sorvala, PE <br />Engineers & Architects <br />February 10, 1988 <br />City of Orono <br />Box 66 <br />Crystal Bay, MN 55323 <br />Attn: Jeanne Mabusth <br />Re: 13935 Co. Rd. 15 <br />Dear Jeanne: <br />Berth A Gordon, PE <br />Thomas W Peterson, PE <br />Charles A Erickson <br />Richard W Foster, PE <br />Michael C Lynch, PE <br />Leo M Pawelsky <br />Donald C Burgardt, PE <br />James R Maland. PE <br />Harlan M Olson <br />Jerry A Bourdon, PE <br />Kenneth P Anderson. PE <br />Susan M Eberlln <br />Mark A Hanson, PE. <br />Keith A Bachmann, PE. <br />Mark A Serp <br />Ted K Field. PE <br />Mark R Rolls, PE. <br />Michael T. Rautmann, PE <br />Robert C. Russek, A.IA <br />Robert R Pfefrerle. PE <br />Thomas E Angus. PE <br />David O Loskota, PE <br />Howard A. Sanford, PE. <br />' E C ' IIE2 'I' <br />We have reviewed the information submitted by Hennepin County relative to <br />flood plain encroachment on the County Road 15 project. The county will be <br />filling in a portion of wetland area 914W. The County will also be working <br />within 75 feet of the Lake Minnetonka shoreline. <br />The total encrochment into wetland 914W is 0.05 acres. The project will not <br />result in any reduction in the water storage area. Excavation of the ditch <br />north of Cou zy Road 15 will cause a slight increase in water storage area. <br />The drainage area that contributes flow to wetland 914W is 27 acres. There is <br />approximately 2.6 acre feet of storage in the wetland which allows the outflow <br />to be controlled at 17 cfs. The culvert under County Road 15 will be <br />increased from 24 inch to 30 inch. The actual control for the wetland is an <br />existing 24 inch culvert on Casco Point Road that is 1.5 feet higher than the <br />invert of the proposed 30 inch pipe. The city could reduce the discharge from <br />the area North of Co. Rd. 15 in the future by dredging out the wetland. <br />The area being disturbed within the 75' setback area of Lake Minnetonka is <br />highlighted on the attached plan. The construction in this area will be above <br />the 931.5 elevation and will not require a permit from the DNR. The plan <br />provides for excavating and filling up to two feet in the area shown. The <br />storm sewer comming from the Hennepin County shop will be upgraded from 18 <br />inches tL 30 inches. Hennepin County will be increasing the pond size near <br />the shop as a part of this project. The drainage area that contributes flow <br />to the pond is 12.5 acres. The pond will allow the outfall to be controlled <br />at 8 cfs. <br />Page 1. <br />01 <br />2335 West Highway 36 • St. Paul, 10innesota 55113 • 612-636-4600 <br />