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<br />Between Mulberry Street and Vine Drive, the Lemay Avenue <br />embankment acts as a dike to block Cache La Poudre flows from going <br />east. This embankment lacked adequate freeboard during the l00-year <br />event but after consultation with the City, it was decided to assume <br />the road embankment provides protection from floods up to and <br />including the l00-year event. <br /> <br />There were several low-lying areas protected from flooding from <br />the main channel by gravel banks with minimtnn freeboard. If these <br />banks fail, these areas would be flooded. Because of this possible <br />hazard, these areas are shown as subject to shallow flooding. <br /> <br />Floodway <br />The floodway is the channel of a stream, plus any adjacent flood <br />plain areas, that must be kept free of encroachment in order for the <br />l00-year flood to be carried without substantial increases in flood <br />heights. For this study, a one foot rise and a one-half foot rise <br />floodway were developed. Preliminary versions of the floodways <br />delineated were provided to the study sponsors for their review. <br />Changes requested by these entities have been included in the final <br />floodway. <br /> <br />In the 1989 SFH study, it was found that the configuration of <br />flows in the lower reach of the study required divided floodways in <br />that area. The flow in the LPATH9l flow path could not be held in the <br />main channel flow without causing an unacceptable increase in water <br />surface elevations. Because of this condition floodways were <br />developed along the main channel flow path and along the LPATH9l split <br />flow path. After the initial floodways were determined in this area, <br />the UMER model was run for floodway conditions (encroachments added <br />and RPATH flow added to main channel) to determine how much the spill <br /> <br />11 <br /> <br />_. .__ _ _,_.~._ .. _.__r__~_._n______u__~_~_,,~~.~_-=-..,...~~~__ <br />