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I I I JamestO\\TI's major drainage-way is James Creek ",,'hich flows from the west to the cast through the to\\'l accepting inflow from Little James Creek as well as various ditches and gulches. James Creck eventually empties into Left I-land Creek approximately 2 miles cast of the town. I I I A FEMA Flo()d Insurance Study (FIS) has been published for EI Paso County including the City of Colorado Springs. The study includes Fountain Creek. Sand Creek. and Cottonwood Creek and was updated in August 23. 1999. A FEMA FIS also exists for Boulder County which includes the Town of Jamesto\vn. The FlS did not study the unnamed gulch that overllowed but did study James Creek and Little .lames Creek in the Town of Jamesto\\TI. The Boulder County FIS was updated May 6. 1996. No site visit was made to the Colorado Springs area for this study however. representatives from the CWCB visited the Jamestovm area on June 28. 2004 to inspect and photograph the damage there. I I Several stream flow gages were available for Fountain Creek in Colorado Springs. According to the precipitation sources mentioned above, the 1110st intense rainfall occurred in the southeastern portion of Colorado Springs near the airport. A USGS stream flow gage is located along Fountain Creek near Security. Colorado. Measured flow data, including data for June 27'h. is sho\\11 for this gage in Figure 1.19 which is courtesy of Mr. Nick Young with the USGS's Pueblo field ollice. The gage's location in relation to the local area and state of Colorado is also sho\VT1 in Figure 1.20. According to this gage. the peak now for the June 2th event was approximately 5540 cr.... I I I I I A USGS now gagc is also located on Cottonwood Creek however. the location of till: gage is upstream of the study limits in the F1S. Therefore. for infonnalional purposes only. the daily mcan flow data for Cottonwood Creek on June 2th as well as its gage location in the state arc ShO\\l1 in the Additional Support Informution section of this report. No flow gages were found for Sand Creek or the unnamed gulch in Jamestown. I A hydraulic frequency analysis can be perfom1cd for Fountain Creek by comparing the peak discharge for the Security gage (5540 cfs) to the established FIS discharges in the El Paso County F1S for Fountain Creek. lIo\'ie\'er. the measured peak discharge is less than the lowest value published in the FIS (12.700 cfs) and thus a frequency estimation using this mcthod would be inconclusive. Also. when examining Figure 1.19 one notices a second peak (4S00 efs) occurring approximately 1.5 hours alter the first peak. This indicatcs some attenuati<m in the measured discharge for Fountain Creek which makes sense considering that several other major drainage-ways. including Sand Creek. flow into Fountain Creek. Each of these contributing drainage-ways has different hydraulic characteristics and thus different times of peak now. One last thing that could explain the inconsistency bctween the measured discharge and the FIS discharges is the size of'thc Fountain Creek drainage area. At the Security gagc location. the contributing drainage area is 495 square miles according to the USGS. This area includes most of the Colorado Springs area as well as t\.1anitou Springs and Green Mountain Falls in Teller County. When one cxamines Figure 1.18. it is apparent that the most intense rainfall occurred in the southeastern portion of Colorado Springs and did not impacl the entin: Fountain Creek drainage basin. I I I I I ICON~ ,_ 10 ~2004