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floods could occur at short intervals or even within the same year. The risk of experiencing a rare flood increases when periods greater than 1 year are considered. For example, the risk of having a flood which equals or exceeds the 100-year flood (l percent chance of annual exc~edence) in any 50-year period is approximately 40 percent (4 in 10); for any 90-year period, the risk increases to approximately 60 percent (6 in 10). The analyses reported herein reflect flooding potentials based on conditions existing in the community at the time of completion of this study. Maps and flood elevations will be amended periodically to reflect future changes. . 3.1 Hydrologic Analyses Hydrologic analyses were carri~d out to establish peak discharge- frequency relationships for 'each flooding source studied by detailed methods affecting the community. For Fountain Creek, flood discharges were computed by the COE in the 1974 Flood Plain Information report (Reference 4). A log-Pearson Type III analysis of streamflow records at the Pueblo gage from 1935, and 1941 to 1965, was used to determine flood frequency (Reference 6). Other gages on Fountain Creek were not used due to short length of record (Colorado Springs and Security) and inaccurate representation of the flood potential of the stream (Fountain) . The Standard Project Floods (SPFs) for Fountain Creek at Manitou Springs, Colorado Springs, the El Paso-Pueblo County boundary, and Pueblo were developed by the COE (Reference 4) using the June 1921 storm. The SPF is defined as the flood that may be expected from the most severe combination ,of meteorological and hydrological conditions that is considered reasonably characteristic of the geographical area in which the :drainage basin is located, excluding extremely rare combinations. Orainage areas above an elevation of 9,000 feet were not included in the SPF computations for Fountain Creek because they do not make a significant contribution to storms of the SPF magnitude. A discharge-drainage area curve was developed and used to compute SPF discharges for Fountain Creek at locations in Manitou Springs. The SPF discharge of 219,000 'cubic feet per second (cfs) at the Pueblo gage is approximately equivalent to the magnitude of the 350-year flood. Based on this, frequency curves for other locations were developed by assigning a recurrence interval of 350 years to each SPF and constructing curves parallel to the frequency curve at the Pueblo gage. These curves were extended to obtain the 500-year discharges for Fountain Creek. From these frequency curves, the 10-, 50-, 100-, land 500-year flood discharges were determined for use in this studl' . .. A frequency analysis of the 'Pueblo gage based on a Type III distribution (Reference 6) was made for this flow records of 1935, 1941 to 1965, and 1971 to 1977. log-Pearson study using In lieu of 8