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the result of the short gage records available for most foothill streams in the Arkansas River basin. In an effort to obtain foothill stream gages with longer periods of record, data from gages in the South Platte River basin were included in the analysis. Again, the gages used were those with drainage areas between 7 square miles and 700 square miles and characteristics similar to foothill streams. The regression equation from this analysis produced a 1-percEmt-change discharge for Oak Creek at Florence of 5,500 cfs wit~ a standard error of estimate of 0.46. Linear Regression Analy,:::is No. 4 on Plate 5 shows that considerable scatter is still evident in pl~:s of gage data from foothill streams in the South Platt€: River basin. Previous ~;tudies on foothills streams in the South Platte River basin have indicated that thE~ upper €,levation limit for significant rainfall flooding is 7,500 to 8,000 feet (Jarrett, 1987) . This Ellevation range marks the transition from large magnitude rainfall-runoff to small ma,gnitude snowmelt-'runoff peak flo.tls; rainfall runoff has not beEm a significant factor in det,:ermining peak flows at streamflow-'ga.qing stations above 7,500 fee-c. As a resu11: of these findings, the drainage area below 8,000 fee~ was measured for the gaging stations used in the regional analysis in bo'ch the South Platte and Arkansas River basins; regression equat,ions were computed correlating the 1-percent-chance flood peak to the adjusted drainage area. The resulting equations did not produce better correlation than did the equations using the ful: drainage areas. Since most of the Arkansas River stations usee! in the analysis are located at Ellevations too low to be considered foothill streams, the predicted runoff peaks were a resul t of the full contributing drainage area, a,nd the analysis did not reflect the relationship between foothill streams and limiting rainfall--snowmelt runoff-peak elevations. DAM BREACH ANAL~'SIS Approximately 4.5 miles from upstream of Florence is an abandoned railroad embankment across, South Oak Creek channel. During a site visit it was expressed that the embankment, acting as a darn, would probably fail at some time in the futurEl during a significant flood. using HEC-l, a model ",as developed to simulate a break and its effect downstream at Florence_ The dimensions of the embankmElnt us,ed in the model are based on the site visit and the USGS Quad map of the area. The dimensions and elevations are rough estimates. The embankment is appr:Jximately 400' long at the top and 3D' high at the center. An appr:Jximately 10 r wide by 14' high box culvert with an inlElt invert 9