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<br /> <br />Federal Emergency Management Agency <br />\*,ashington~ D.C. 20472 <br />September 25, 2008 <br /> <br />The Honorable Tom Gamec .. <br />Mayor~ City of Ramsey <br />7550 S~nwood Drive Northwest <br />FUunsey,MN 55303 <br /> <br />IN REPLY REFER TO: <br />Case No.: 08-05-2729R <br />- Community:- City'bfRamsey, MN- <br />Community No.: 270681 <br /> <br />CERTIFIED MAIL <br />RETURN RECEIPT REQUESTED' <br /> <br />104 <br /> <br />Dear Mayor Gamec: <br /> <br />This responds to a request that the Department of Homeland Security's Federal Emergency Management <br />Agency (FEMA) comment on the. effects that a proposed project would have on the effective Flood <br />Insurance Rate Map (FIRM), Flood Boundary and Floodway Map (FBFM), and Flood Insurance Study <br />(FIS) report for yourcomrnunity in accordapce with Part 65 of the National Floodlnsurance Program <br />(NFIP) regulations. In a letter dated March 27, 2008, Mr. Duane Hansel, P.E., Bolton and Menk, Iilc., <br />requested that FEMA evaluate the effectS that a revised hydrologic and hydraulic analysis, updated <br />topographic information, and the proposed project would have. on the flood hazard infonnation <br />shown on the effective FIRM, FBFM, and FIS report along Trott Brook-from approximately 1~600 feet <br />upstream of Ennine Boulevard Northwest Culvert to appro?,imately 700 feet downstream. The <br />proposed project includes replacement ofan existing 72-inch reinforced concrete pipe culvert at <br />Ermine Boulevard Northwest Crossing with a 14-feet wide by 6-feet high boX: culvert. The area affected <br />by this request is in a flood zone designated Zon~Al, a Special Flood Hazard Area (SFHA), an area <br />subjectto inundation by the base (l-perceht-annual-chance) flood, with Base Flood Elevations (BFEs) . <br />determined. <br /> <br />Ail data required to complete our review ofthis request for a Conditional Letter of Map Revision <br />(CLOMR) were submitted with letters from Mr. Hailsel. . <br /> <br />We reviewed the submitted data and the data used to prepare the effective FIRM and FBFM for your <br />community and detc;:rmined that the proposed project meets the minimum floodplain managemeritcriteria <br />of the NFIP. The submitted existing conditions HEC-RAS hydraulic computer model, dated <br />February 23, 2008, based on updated hydrology, was used as the base conditions model in our review of <br />the proposed conditions model for this CLOMR request. We believe that, if the proposed project is <br />constructed as shown on the topographic work map entitled "City qf Ramsey, Anoka County, Minnesota, <br />Ermine Boulevard Northwest Proposed FIRM/Floodway," prepared by Bolton and Menk, Inc., dated <br />February 2008, and the data listed below are received, a revision to the FIRM and FBFM would be <br />warranted. <br /> <br />The effective hydrology for Trott Brook was computed using regression equations, resulting in a base <br />flood discharge of approximately 660 cubic fe.et per second (cfs) for the project reach. A Hydraulic <br />Engineering Center Hydrologic Modeling System (HEC-HMS) hydrologic computer model was used to' <br />detennine revised discharges for Trott Br~:lOk from its headwaters ill Anoka County to its lowest extent in <br />Sherburne County: The revised hydrology waS prepared by Barr Engineering and approved by the <br />Minnesota Department of Natural Resources. There are significant differences between the revised <br /> <br />55 <br />