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the bridge. Additional bridge input documentation is presented in Appendix RW -E of the <br />1 <br />CLOMR request. <br />The flowrate within Reed Wash used in the HEC -RAS computer model for the <br />Developed Condition is the 100 Year Storm Event of 1,861 CFS at the bridge. <br />The affect of the construction of the bridge upon the existing floodplain is documented in <br />Table RW -1 of the CLOMR request. As shown on Table RW -1 the maximum increase in <br />the 100 Year Water Surface elevation between Historic and Developed conditions as a <br />result of the construction of the bridge occurs at cross section #17, river station <br />3,371.87. This cross section is located approximately 29.17 -feet upstream of the <br />centerline of the bridge. The calculated increase in the 100 Year Water Surface <br />elevation at cross section #17 is 0.61' based on a Developed Condition (DC) Water <br />Surface elevation of 4,459.89. This increase in Water Surface Elevation is below the <br />1.0 -foot maximum allowable increase as defined by FEMA and results in a freeboard of <br />1.75 -feet between the Bottom Chord of the bridge and the (DC) Water Surface elevation. <br />1.5 Conclusions <br />The proposed bridge as designed has adequate capacity to convey the 100 -Year Storm <br />Event of 1,861 CFS while providing at least 1.0 -foot of freeboard between the bottom <br />chord of the bridge and the calculated Developed Condition Water Surface Elevation. <br />The post construction 100 Year Water Surface shall be contained within the Reed Wash <br />channel and will not inundate or otherwise have an adverse affect on the land adjacent <br />to the channel. <br />Prepared By_ <br />Monty D. Stroup <br />Project Manager <br />Colorado Civil Technologies, Inc. <br />1231 North 23rd. Street, Suite #204 <br />Grand Junction, Colorado 81501 <br />Phone (970- 256 -7700) <br />