Agenda - Council - 10/23/2018 - Laserfiche WebLink

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Review File: National Self Storage, Regency Ponds Site Plan Submittal Engineering Review February 7, 2017 Page 2 of 3 C 3.1 1. Per general comment #1, a legend is required showing all symbols used on the sheet. 2. A clay liner must be installed in the pond below the 100-year HWL. A liner is required to comply with the current rules for no infiltration on this project. 3. Add the following to note 9. "Streets must be swept within 3 hours of notification from the City that sweeping is required. C 3.2 1. Add the following under termination of coverage "The City mu approve the Notice of Termination prior to submittal. All Erosion Control inspectiomust be submitted to the City prior issuance of the Certificate of Occupancy." C 4.1 1. Note 13 the correct City contact is Mike McDowall. Stormwater Calculations A stormwater summary report was submitted viewed. The report identifies 3 drainage areas on the existing site and tabulates the 100 year storm. The discharge points for the age areas are Ramsey Boulevard, Bunker Lake Boulevard and the existing pond in the egency Pond development to the east. The report also tabulates the proposed runoff for these same drainage areas. The City finds that the proposed runoff rates are different than reported in the table. The table below shows the difference observed for Ramsey Boulevard. Event 2 yr. 10 yr. 100 yr. the existing condition for the 2, 10 and Boulevard (2S, 5P) x(140eRamsey Proposed Difference 0.9 +0.9 1.6 +1.5 1.8 4.3 +2.5 The Ramsey Boulevard and Bunker Lake Boulevard storm sewers were not designed to accommodate runoff from the adjacent properties. An analysis of these systems will be required to demonstrate that adding water to the system will not increase the spread on the pavement. This project will be required to contribute to the infiltration mitigation fund in lieu of installing infiltration on site. The amount of the contribution is the estimated cost to construct an infiltration basin sized for this project. The project engineer prepares the calculations and the City reviews the calculations and recommends the amount to be included in the Development Agreement.