5.8. SR 12-19-1994
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ITEM 5.8.
MEMORANDUM
River TO:
Mayor & City Council
FROM: Pat Klaers, City Administrator
DATE: December 19, 1994 r
SUBJECT: Detailed Analysis of Surface Water
Issues in the Western Area
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Attached for your review is a memo from the City Engineer regarding surface
water management work that needs to be done in the western area of our
City now that development is taking place. I concur that this work should be
done in order for surface water management issues to be adequately
addressed as development goes further west. As a City, we have not
previously undertaken this type of detailed work prior to development. One
reason why we have not done this type of work in the past is that we have not
had large areas open for development that necessitated a detailed surface
water management analysis. When development pressures cause utilities to
go east, I can envision a similar type of analysis being necessary.
With additional surface water management costs accumulating, it may be
necessary for us to reevaluate the lateral storm sewer rate of $6.00 per foot.
This is far below the actual cost of lateral storm sewer pipes and we may
need to recapture more of the actual expenses through this assessment
process. No action is requested on our assessment rates at this time, but we
will need to discuss this issue in early 1995. At this time, the expenses
outlined in the attached memo, along with the previous expenses authorized
for the two foot contour aerial topography, will be costs that will be financed
through our surface water management fund.
council:detanaly
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13065 Orono Parkway · P.O. Box 490. Elk River, MN 55330. (612) 441-7420. Fax: (612) 441-7425
MS ~
l'ONSII/J1ING ~;NllINEERS
1326 Energy Park Drive
St. Paul, MN 55108
612-644-4389
1-800-888- 2923
Fax: 612-644-9446
CIVil ENGINEERING
ENVIRONMENTAL
.MUNIClPAl
PlANNING
SOLID WASTE
STRUCTURAL
SURVEYING
TRAffiC
TRANSPORT A TION
ELECTRICAl/MECHANICAL
ENGINEERING
HVAC
POWER DISTRIBUTION
SCADA
SYSTEM CONTROlS
_OFFICES IN:
INNEAPOLlS
PRIOR LAKE
S1. PAUL
W ASECA
December 15, 1994
File: 230-000-00
Mr. Pat Klaers
City Administrator
City of Elk River
P.O. Box 490
Elk River, MN 55330-0490
RE: DETAILED WESTERN AREA SURFACE WATER MANAGEMENT PLAN
Dear Mr. Klaers:
As you are aware, the City Council has recently authorized the acquisition of 2 feet contour
aerial topography for the remaining undeveloped portion of the Western Area. We are
currently in the process of completing the survey ground control to submit to Mark Hurd
& Associates, such that they can provide the aerial topography to us. That. aerial
topography will be very useful in proceeding with the next step in the Comprehensive
Storm Drainage Plan for this area. That step would be the detailed layout of a storm sewer
system. The detailed system would provide the following information:
· Delineate watershed basins on an after-development basis.
· Model the existing peak discharges from each of these watershed basins.
. Model the preliminary proposed peak discharge from each watershed basin using
the fully developed conditions, given the recent rezoning of the area.
. Develop a preliminary stormwater plan to satisfy both the stormwater detention
requirem~nts as necessary, and also water quality requirements.
. Develop a preliminary pipe network consisting of main trunk sewer and outlets for
each stormwater pond, including pipe sizes, elevations, alignments, and peak flows.
· Identify t..'le outlet for each area and the maximum flow rate.
· Prepare detailed cost estimate of the proposed improvements.
. Summarize conclusion and recommendations in a written report, including Exhibits,
which can be utilized by developers of the area.
As you are aware, the areas that have currently developed in the Western Area were done
prior to a detailed stormwater plan, such as the one outlined above. This caused many
issues to be raised, such as which areas should flow into which pipes, where ponds should
be located, and whose stormwater could run into which pond. By completing a detailed
plan prior to additional development in the area, we should be able to minimize, if not
eliminate these types of issues in the future. The cost of such a plan could be included with
the costs of the stormwater system to be constructed since it constitutes a preliminary
design, and eventually assessed back to the developing and benefitting areas as part of the
overhead costs for the storm drainage facilities.
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Mr. Pat Klaers
December 15, 1994
Page Two
We have recently been approached by John Oliver & Associates, who represent developers
considering additional developments in this Western Area. They have begun to ask
questions relative to detailed storm sewer systems such as flow rates, maximum outlet rates,
pond sizes and locations, and direction of watershed basin flow. At this point in time, we
are unable to answer these questions, due to lack of a detailed plan for the actual
construction of drainage facilities for this area. Therefore, we would recommend that the
City undertake this type of planning immediately, given the eminent development of
additional areas. We would estimate the cost to complete such a study for the entire
remaining unsewered portion of the Western Area to be $17,500. We believe a preliminary
draft of the study could be available by mid to late February, in time for discussion at the
City's annual Capital Improvements Plan Workshop. As always, we would use this
maximum cost as a not-to-exceed amount, and bill for our services hourly up to that
amount.
Please let me know how you would like us to proceed on this issue. If you have questions
or need additional information, please call.
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Sincerely,
MSA, CONSULTING ENGINEERS
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Terry J. Maurer, P.E.
TJM:pd
000-1407.dec
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