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1993-08-30 Drainage Albertville & Frankfort Special AgreementMEYER-R01-fUN, INC. ENG/A'EERS-LAND SURVEYORS 1111 Nvey. 25 N., Buffalo, Mirn.55313 Phone 612- 682-1781 August 30, 1993 Lori Vanderhider, District Agreements Engineer Minnesota Department of Transportation, District 3 1991 Industrial Park Road Baxter, 14N 56401 RE: Albertville and Frankfort Drainage S.P. 8680-126 (I-94) Special Agreement Dear Ms. Vanderhider: Enclosed are the preliminary plans, cost estimates and rationale for the above -referenced project for your review and approval. Once MnDot's comments have.been received, final Plans and Specifications will be completed. Although this project may appear to have been dro unusually wet summer and resulting high water conditions ped, the the seasonal autumgaited the Cit n rains have reignited � prior to y s concern. Considering the specific public benefits in conjunction with Possible property damage and losses to Interstate 94 and local businesses, the City formally requests that this project be allowed to proceed this construction season. It is our understanding that this type of project can not proceed until a special agreement contract has been signed by all parties involved. If the State is unable to approve this project and funding this season, the City would like to propose, if any way possible, that the City would cover all costs initially with the understanding that MnDOT would contribute a MnDOT determined amount at a later date. Meyer-Rohlin; Inc. and the city of Albertville are looking forward to working with MnDOT on this project. If you have any questions, please do not hesitate to call me. Sincerely, MEYER-ROHLIN, INC. Ronald Geurts Engineer cc: E-9001-H City of Albertville Frankfort Township Thore P. Meyer, Professional Engineer Robert Rohlin, Licensed Land Surveyor GOAL The goal of this project is to eliminate existing flooding conditions in the northeast portion of the city of Albertville. PROBLEM Several typical rainfall events in saturate and flood the surrounding local streets and Interstate 94. quick succession have the ability to areas, including homes, businesses, GIVEN The watershed's three contributing areas can be segregated as follows: Total Benefited Area Wetlands Area 1. Albertville Area 1 68.01 17.41 50.60 Area II 12.21 4.68 7.53 80.22 22.09 58.13 2. Frankfort* Potter's Commercial Park 16.12 6.07 10.05 Green Haven Estates 38.92 Cemetery --- 38.92 3.33 - 3.33 58.37 6.07 52 30 3. Mn/DOT* 38.2 ---38.2 176.79 28.16 148.63 * Acreage provided by Frankfort Township Engineer, Pete Raatikka (9/16/90). PROPOSAL The existing high water mark has a footprint of approximately 45-50 acres and is capable of handling large storm/rainfall events (50-year plus). Although the retention area is quite large, the existing drainage outlet is sized comparatively too small. Historically the outlet was an 18-inch drain field line. Our understanding is that during the summer of 1991 a portion of this line was replaced and reduced to an 8-inch line. Since then, during frequent rainfall events, the retention area accumulates new volumes before the previous volume has completely drained. Our intention is to provide a surplus outlet. The outlet is not designed to handle any specified rainfall event, but to provide a more rapid relief under high flood waters. The proposed outlet invert has been set based on the outlet invert from the nearby DNR protected wetland (415W, 947.74MSL). As can be determined by the attached support documentation, this proposed outlet will provide relief from high flood waters in a matter of a few days. Using a worse case scenario of a 50-year storm event and assuming that the existing outlet to the northeast is absent, the proposed outlet will remove the total volume of 43.2 acre-feet in 7.3 days. (12" RCP @ 3.0 c.f.s. ) Understandably, this outlet is not expected to drain the complete storm event, but has the ability to lower the base elevation in the retention area to 947.75 MSL. Assuming this was the static elevation prior to a 50-year storm event, the flood level would rise to approximately 949.0 feet. The existing water elevation is 950.50, approximately 2.5 feet below the centerline of east -bound I-94. COST ESTIMATES 12" RCP @ .6%, 1022 l.f. @ 17.00 = $17,374.00 12" RCP flared end w/trash guard = 500.00 65' RCP jacking under railroad w/30" steel casing @ 120.00/ft. 7,800.00 2 standard 27" RCP manholes @ 600.00 = 1,200.00 1 standard 60" RCP catch basin @ 1500.00 = 1,500.00 1 connection to existing system @ 800.00 = 800.00 430' ditch excavation @ 5.00/ft. = 2,150.00 Seeding & mulching, 1.1 acre @ 1000.00 (restoration) = 1,100.00 Sodding, 100 S.Y. @ 2.00 = 200.00 Estimated construction $32,624.00 Engineering S contingency 6,500.00 Estimated Project Cost $39,124.00 COST SHARING Several methods and variations have been proposed locally for cost sharing. The generally agreed upon concept is that each governmental body involved should participate based on percent of total rainfall runoff contributed to the retention area. Once MnDOt has determined what portion of the project costs it is responsible for, the remaining portion will be shared upon mutual agreement between the City of Albertville and Frankfort Township.