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The City of Woodland Park is dev~loping rapidly. New residential and commercial development, alon~ with the paving of streets, has resulted in a greater proportion'of impervious areas within the corporate limits. However, the percentage of developed area within the flood plains is still!small. 2.3 Principal Flood Problems No official record of flooding events within the City of Woodland Park exists. However, based on ~ocal observations, the peak runoff events are generated fromithunderstorms. Newspaper and historical summaries show that in 1902 a thunderstorm centered on Woodland Park and destroyed all ~ridges on Fountain Creek from the city to Manitou Springs, a distance of 12 miles (Reference 5). In June 1973, flooding throughout Woodland Park resulted from a thunderstorm and was severe enough to warrant the approval of State disaster relief funds. On July 29, 1984, a very localized thunderstorm dropped 2.75 inches,of rain in 30 minutes on the middle reach of Fountain Creek, washing out a newly installed 6- foot-diameter culvert at the confluence of Fountain and Crystola Creeks. The frequency of these events can only be estimated, as no flow record is available for analysis. The recurrence interval of the 1902 storm was estimated as 50 years or more, based on the capacity of major structures damaged. The 1973 storm damaged local drainage structures, but did not cause major structural damage. The 1984 storm flow had:to have been greater than 400 cubic feet per second (cfs) to cause the failure of the culvert. A 400-cfs flow is estimated to have a recurrence interval of 2 years or less. No deaths due to flooding within: the study area were recorded. Flooding problems due to the more frequent storms are to a large degree a result of local drainage problems. The drainage system within most of the developed area of Woodland Park was built to convey not more than the 5-year event, in compliance with criteria adopted by the City (Reference 6). In many areas, the natural channels have been modified by d~velopment activities so that their conveyance capacity is les$ than it was originally. These modifications include local constrictions such as culverts, the diversion of a channel, and cons~ruction or filling within the channel and flood plain. i Sedimentation is a concern within the project area. Highly erodible soil results in regular!blockage of culverts and local drainage structures. Aggradation of the streambed is evident in several reaches of Fountain Cree~ within the study area. 6