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14. Nelson, Haley, Patterson and Flood Study for Scale 1" = 100', contour & Quirk, Inc., Comprehensive Drainaqe Florence, Colorado, February 1977, interval=2 feet. 10.0 REVISION DESCRIPTIONS This section has been added to provide information regarding significant revisions made since the original Flood Insurance Study was printed. Future revisions may be made that do not result in the republishing of the Flood Insurance Study report. To assure that any user is aware of all revisions, it is advisable to contact the community repository of flood-hazard data located at Fremont County Office, 300 West Main, Florence, Colorado 81226. 10.1 First Revision This study was revised on March 17, 2002, to incorporate a hydraulic analysis of Oak Creek (including its right and left bank overflows) from its confluence with the Arkansas River to the abandoned Atchison, Topeka & Santa Fe Railroad. The hydraulic analysis for this revision was perfomed by the Albuquerque District of the U.S. Army Corps of Engineers, for the Federal Emergency Management Agency under Interagency Agreement No. EMW-98-IA-0176, Project Order No.9. The work was completed in October 1999. Discharges were taken from the 1991 hydrologic analysis of the Oak Creek basin prepared by the Albuquerque District of the U.S. Army Corps of Engineers (Reference 11). The hydraulic characteristics of the flooding sources were analyzed to provide flood plains for the l- and O.2-percent-chance floods and estimates of the water surface elevations for the 10-, 2.0-, 1.0-, and 0.2-percent-chance floods along the flow paths studied in detail. The water surface elevations were computed using the computer program HEC-RAS (Hydraulic Engineering Center-River Analysis System), developed by the U.S. Army Corps of Engineers Hydrologic Engineering Center (Reference 12), and based on cross-sectional data generated from field surveyed data and mapping provided by the City of Florence. Structures that affect the hydraulic computations were field checked to obtain pertinent dimensions. The flood profiles show the locations of cross sections used in the hydraulic analysis and the computed water surface elevations. The hydraulic analyses for this revision were based on unobstructed flow. The flood elevations shown on the profiles are thus considered valid only if hydraulic structures remain unobstructed, operate properly, and do not fail. The City of Florence identified Oak Creek as having potential flood hazards during storm events. Based on discussions with City representatives, a hydraulic baseline was drawn along the centerline of Oak Creek. The width of the cross sections varies based on the extent of the flood plains. The lower limit of this revision is approximately 330 feet upstream of 16