1994-07-01 Drainage Frankfort Twshp & MnDOT,_
MEYER-ROHLIN, INC. L~ U ~
ENGINEERS-LAND SURVEYORS 1111 Hwy. 25 N., Buffalo, Minn.55313 Phone 612- 682-1781 O /-~
July 1, 1994
City of Albertville
c/o Dale Powers, Administrator
Box 131
Albertville, MN 55301
RE: Frankfort Township and MnDOT Drainage
Albertville, Minnesota
Honorable Mayor and Council Members:
Per your June 20, 1994,. request, enclosed is a status report for
the above-referenced project.
Our last. contact with MnDOT occurred during August and September
of 1993 (letters enclosed). At that time we proposed immediate
construction of the referenced 12" RCP storm outlet to the south
and associated drainage. MnDOT's September 20, 1993 response
required additional research to be completed before any
reimbursable construction could begin.
Simultaneously Frankfort Township, in response to high water
encroaching on the Green Haven Estates, created a surface
drainage ditch to the northeast. This ditch begins at the 18"
clay and 8" HDPE junction and drains to the east along the
existing drainage easement north of Green Haven Estates.
A summary of collected data and elevations as shown on the
enclosed plan sheets and recent letters is as follows. A list of
available options is also presented.
- The proposed inlet invert elevation for the 12" RCP is
947.50'. This could be lowered to 944.65' but would require a
larger pipe size.
- The recently constructed ditch to the east is capable of
handling a 100-year storm event. The ditch has a minimum
drainage elevation of 948.6' (12/93).
- The inlet invert elevation of the 8" HDPE perforated drainage
pipe is 945.75'. This is 1.10' below the existing water level
(946.85; 6/29/94). The 8" HDPE does work and is free-flowing.
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Thore P. Meyer, Professional Engineer Robert Rohlin, Licensed Land Surveyor
City of Albertville
Page 2 -
OPTION 1
The first option is to install the 12" RCP and drainage ditch to
the south as proposed in our August 30, 1993, letter to MnDOT.
This would require the completion of the extra Work as
identified in the September 20, 1993 MnDOT response letter or
accept a lesser financial reimbursement, approximately 25% of
the project cost. A larger percent has not yet been guaranteed
by MnDOT. The amount is yet to be determined by MnDOT depending
on available funds and watershed percent contribution. Based on
acreage alone, the percentage is 22%.
The total cost for this option is approximately $40,000.
OPTION 2
The second option is to increase the pipe size and lower the
inlet elevation for option 1.
The issue present with this option concerns the nearby DNR
wetland (415W) as'well as the lowlands along I-94 and the
northeast quadrant of Barthel Commercial Drive and Burlington
Northern Railroad. Any activity within a wetland requires DNR
notification and permit application. Sfnce the above-mentioned
lowlands would be severely impacted (drained) the DNR may
require wetland mitigation and relocation. The DNR may also take
exception to the additional impact on the wetland on the
northeast side of I-94; an additional 1.10' water elevation
drop. (944.7)
The cost increase for 15" RCP and a deeper ditch would be
$6,500, not accounting for any DNR related fees or costs and
additional work.
OPTION 3
The third option is to observe the current condition and whether
the Frankfort Township drainage to the northeast will provide
proper relief for both sides of I-94. Investigation of the
drainage pathways and related water elevations indicate option 3
will provide rapid relief during large rainfall events. The
existing 8" HDPE perforated drain pipe to the east has the
capacity to provide additional relief.
If you have any questions, please do not hesitate to contact me.
Sincerely,
MEYER-ROHLIN, INC.
Ronald Geurts
Engineer
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cc: 9001-H