5.8. SR 12-19-1994 - Laserfiche WebLink

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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.