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Updated Surface Water Management Plan (SWMP) <br />City of Ramsey, Minnesota <br />Wet water quality ponds upstream of dry regional infiltration basins (where possible) will <br />help control the rate and the volume of storm water runoff. To provide flood protection <br />for adjacent property, the design storm interval for ponding areas is a 100-year storm as <br />compared to a 10-year storm for design of storm sewer piping. Any new residential, <br />commercial, industrial and other habitable structures shall be constructed with the <br />following low floor elevation: The low floor elevation of all development, including <br />basements, must be at least 3 feet above the highest anticipated ground water table, 2 feet <br />above the designated or designed 100-year flood elevation, or 1 foot above the <br />emergency overflow, whichever is higher. The area of a pond's HWL plus 1 foot of <br />freeboard shall be contained entirely within an outlot that is owned and maintained by the <br />City or within a drainage and utility easement. <br />In areas adjacent to designated flood plains as mapped on a Flood Insurance Rate Map, <br />the Regulatory Flood Protection Elevation (RFE) applies. The RFE is defined as the <br />mapped 100-year flood elevation plus 1 foot. However, the LRRWMO requires that the <br />low floor elevation of structures be 2 feet above the calculated flood elevation. Therefore, <br />all structures, including accessory structures, must be elevated on fill so that the lowest <br />floor including basement floor is lft above the Regulatory Flood Protection Elevation or <br />2 foot above the mapped 100-year flood elevation. The finished fill elevation for <br />structures shall be no lower than the Regulatory Flood Protection Elevation and the fill <br />shall extend at such elevation at least fifteen (15) feet beyond the outside limits of the <br />structure erected thereon. The following drawing better defines the Regulatory Flood <br />elevations.' <br />6 Taken from the Minnesota DNR website: <br />http://www.dnr.state.mn.us/waters/watermgmt_section/floodplain/rfpe.html <br />Section IV <br />October 21, 2015 Page 32 <br />