1993-08-30 Ltr Re: Prelim Plans1Vf~Y~1-~-R~1-{L1~1,11~C.
ENGINEERS-LAND SURVEYORS 1117 Kwy. 25 N., 6u(falo, lvfirn.55313 Phone 612- 682-1781
August 30, 1993
Lori Vanderhider, District Agreetrents Engineer
Minnesota Department of Transportation, District 3
1991 Industrial Park Road
Baxter, IfN 56401
RE: Albertville and Frankfort Drainage
S.P. 8680-126 (I-94)
Special Agreement
Dear Ms. Vanderhider:
Enclcsed 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
wi 11 be corc~pleted .
Although this project may appear to have been dropped, the
unusually wet su:-nmer and resulting high water conditions prior to
the seasonal autunn rains have reignited the City's concern.
Considering the specific public benefits in conjunction with
pessible 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 NuzDOT 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
cop L
The goal of this project is to eliminate existing flooding conditions in
the northeast porticn 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 Eenefited
Area h'etlands 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*
Fotter's Commercial Park 16.12 6.07 10.05
Green Haven Estates 38.92 --- 38,02
Cemetery 3.33 --- 3.33 ,
58.37
6.07 _
52.30
3 , idn/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.
c?ur 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).
A s 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 aQSent, the proposed outlet
will rerove the total volune 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
SO-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 ESTIIrIATES
12" RCP @ .6ti, 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 Z; mulching, 1.1 acre @ 1000.00 (restoration) = 1,100.00
Sodding, 100 s.y. @ 2.04 = 200.00
Estimated construction $32,624.00
Engineering t; 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 stared upon
mutual agreement between the City of Albertville and Frankfort Township.
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