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<br />DR Af.r <br /> <br />determined. One for the gages excluding those along the east side <br />of the Gore Range and an alternate value for the stations along the <br />east side of the Gore Range. The former regional skew coefficient <br />and its weight are -0.34 and 0.1. The values for the stations <br />along the east side of the Gore Range are a regional skew culvert <br />of 0.47 and a weight of 0.2. <br /> <br />In performing initial analysis there were two stations which were <br />consistently low relative to other stations. These were Otter <br />Creek above Green Mountain Reservoir (09055000) and Keystone Gulch <br />near Keystone (09047700). Reviewing topographic maps showed that <br />these two basins did not have a significant portion of their <br />watershed in the high mountain area above 11,500 feet. Therefore, <br />these two basins were excluded from the final regional analysis. <br /> <br />Results <br /> <br />From application of the FFAN model utilizing the methodology in <br />Bulletin '17B, the peak discharges for the individual stations were <br />determined for the 2-, 5-, 10-, 25-, 50-, and 100-year annual <br />floods. The resulting peak discharges are shown in Table 2.3. <br />These values represent the "expected probability discharge" values. <br /> <br />TABLE 2.3-RESULTS OF FREQUENCY ANALYSIS AT INDIVIDUAL STATIONS <br />--------------------------------------------------------------- <br />STATION AREA 2-YR 5-YR 10-YR 25-YR 50-YR 100-YR <br />NO. (SQ. MI.) <br />---------------------------------------------------------------- <br />Combined* 119. 593 855 1010 1200 1330, 1540 <br />09047000 128. 702 913 1040 1180 1270 1360 <br />09046600 119. 469 765 979 1270 1500 1740 <br />09047500 57.7 555 757 880 1030 1130 1230 <br />09047700** 9.1 40 66 85 111 132 153 <br />09050100 93.3 980 1290 1470 1680 1830 1973 <br />09050500 111- 1080 1380 1560 1760 1910 2040 <br />09051000 12.8 149 179 197 222 241 261 <br />09051500 13.5 142 174 194 220 239 259 <br />09052000 15.8 194 235 257 283 301 317 <br />09052400 8.6 160 214 254 312 361 418 <br />09052500 9.8 159 206 244 304 362 435 <br />09052800 14.2 226 294 346 423 490 567 <br />0905300 16.6 179 234 274 334 387 448 <br />09054000 15.0 269 337 387 457 515 578 <br />09054500 18.2 255 337 401 503 600 719 <br />09055000** 9.4 54 79 99 131 162 201 <br />09055300 12.0 224 280 320 375 421 472 <br />09055500 14.4 269 336 386 461 539 608 <br />07083000 23.6 265 335 412 483 536 587 <br />07086500 67.1 574 792 932 1110 1230 1360 <br />---------------------------------------------------------------- <br /> 7 <br />