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<br />Updated Storm Water Management Plan (SWMP) <br />City of Ramsey, Minnesota <br /> <br />Because the majority of the area is served by large stream/wetland complexes, <br />regional ponding is not possible for a significant part of the city. Where they are <br />possible, the creation of regional ponds is preferred because of the limited <br />maintenance (compared to a multitude of individual development ponds) and the <br />opportunity to control larger drainage areas. By contrast, a multitude of scattered <br />ponds associated with each individual site development may be designed to <br />reduce the peak outflow for its smaller area, by storing the excess runoff and <br />releasing it at a lesser rate for a longer duration. This longer pond outflow <br />duration may coincide with the reduced peak flows from other individual site <br />ponds and create a larger combined peak flow than the original undeveloped <br />condition. Hence, regional ponds are recommended where physically possible, <br />because of the opportunity to control the runoff on a larger scale and ensure that <br />the downstream system is not adversely impacted by uncoordinated development <br />that meets a typical runoff ordinance. The greater control afforded by regional <br />ponds may also reduce the flows to the downstream system and allow for <br />decreased costs in downstream infrastructure improvements. <br /> <br />4. The proposed infiltration requirements and pond network is part of the goal of <br />accommodating continued responsible growth. Revisions will be required as <br />formal developer layouts are presented to the City. Although this plan forms a <br />sound basis for future development, it is important to remain flexible in finding <br />ways to manage runoff while still accommodating the continued development of <br />the city. <br /> <br />5. The maps attached at the end of this report are for general illustration purposes. <br />As part of the plan development, large ,gcale maps and GIS compatible files have <br />been prepared and will be downloaded into the City system upon full approval of <br />this plan. The GIS maps and files show more detailed information including <br />watershed areas, proposed pond areas and storage volumes, estimated flow rates <br />into and out of the proposed ponds for both the existing and developed <br />conditions, proposed interconnecting pipe sizes between ponds, etc. <br /> <br />6. The City will pursue outside funding to help finance the recommended capital <br />improvements described in this plan. Local financing will most likely come from <br />a combination of st~rm sewer trunk fees and the City's storm water utility fund. <br /> <br />Any determined storm water management charges or area charges to new <br />developments should be reviewed on an annual basis to ensure that changes in <br />land acquisition, construction cost, bonding cost, legal cost, etc. are included in <br />the computed fee. <br /> <br />7. The use of native vegetation for buffers in undeveloped and previously <br />developed areas is strongly recommended in the Wetland Management Plan <br />(Appendix C). <br /> <br />8. This SWMP includes a complete wetland functions and values assessment as part <br />of a greater wetlands management plan. The functions and values assessment <br />worksheets will be added to the City's GIS system as a "smart map" with pull <br />down menus associated with each mapped wetland. <br /> <br />~ Bolton & Meflk. Inc. 2008. All Rights Reserved <br />Section II <br /> <br />Page 6 <br /> <br />M13.39530 <br />October 13,2008 <br />-198- <br />