1994-05-27 Drainage Area
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MEYER-ROHLIN, INC.
ENGINEERS-LAND SURVEYORS 1111 Hwy. 25 N., Buffalo, Minn.55313 Phone 612-682-1781
May 27, 1994
Mr. Bob Robertsen
RCM
10901 Red Circle Drive
Minnetonka, MN 55343
RE: Psyk/Marx Drainage
Albertville, MN
Dear Bob:
As per a discussion with Mike Couri, City Attorney for
Albertville, he requested the following information be forwarded
to you regarding the development of the psyk' s 5th and 6th
Addition~.
1
Exhibit 1 indicates the drainage area before any development was
started on the psyk properties. Approximately 30 acres of the
psyk property surface-drained generally to the northeast into
the large wetland area on the Marx property.
Exhibit 2 indicates the area, after development of the 5th and
6th Additions, that will be draining to the northeast into the
Marx wetland area. This approximates 7.9 acres. The remaining
22.2 acres of drainage area will be diverted into a drain-dry
detention pond outletting into the existing 5th Addition storm
sewer, sedimentation pond and wetland area.
Enclosed also are the drainage calculations for the pre-
development 30 acres and post-development 7.9 acres. Based on 30
acres of row crop farmland, the 50-year storm event would
generate approximately 8.0 acre-feet of total runoff to the
northeast. The 50-year storm event for the 7.9 acre residential
(1/3 acre lots) development calculates out. to be about 1.6
acre-feet of total runoff to the northeast, substantially'less
than the original conditions.
Exhibit 2 also indicates a possible location for the storm sewer
to collect and dispose of storm water from the 7.9 acres of
Psyks 6th Addition and approximately 5.9 acres of existing
drainage from the Marx property. This location would most likely
change when a revised preliminary plat for the Marx property
Thore P. Meyer, Professional Engineer Robert Rohlin, Licensed Land Surveyor
d"
.
/;J
y
Bob Robertsen
page 2
would be designed working around the wetlands, as would the Marx
drainage area, which could increase substantially. I have used
these basic areas, however, to arrive at a preliminary storm
sewer design and anticipated costs. The five-year storm event
for the storm sewer design would result in 18" and 21" RCP and
Dual Wall Polyethylene pipe. The estimated storm sewer cost,
including a sedimentation basin with an outfall structure to the
wetlands, would be approximately $15,000.00.
By the development of the psyk property in the manner proposed,
the runoff from the psyk property to the northeast (into the
Marx wetland) has been substantially reduced. The storm sewer,
with the sedimentation pond, properly disposes of the balance of
the storm water runoff from the psyk property and a portion of
the Marx property. As the alignment of the proposed storm sewer
would be dependent upon the future development plans of the Marx
property and is not known at this time ,I it would appear that an
escrow amount, based upon the contributing areas, could be
established for the psyk property so that the development of the
psyk 6th Addition could continue.
If you have any questions, feel free to contact me.
Sincerely,
cc: Mike Couri
Doug psyk v
File 94120
ore Meyer
Professional
enclosures