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e The climatl of Manitou Springs is characterized by cold winters and warm s~mmers with cool evenings. Mean temperatures in the area rangel from 28.6oF in January to 70.70F in July. On pike's Peak, the mean temperatures range from 20F in January to 400F in July. rl recipitation in the area falls mainly from April to August and averages l5.73 inches per year (Reference 2). The heaviest r corded rainfalls have come in late May and early June when the t~mperature contrast is greatest between the warm surface air and cobl upper air. The upper air is still very cold to the north, butl surface air has begun to he~t up rapidly to the south. I This maxim~m contrast causes the heaviest general precipitation. The Manitou Springs area is subject to a meteorological phenomenon known as ct'OUdbursts. They are confined chiefly to the eastern foothill r gions below an elevation of 7,500 feet and extend eastward toward the plains for a distance of approximately 50 miles. Cloud- bursts dev lop when there is a marked range in temperature within a relative y small area and occur in the afternoon or early evening of an unushally warm day. Cloudbursts are characterized by rainfall of great i~tensity confined to a very small area and lasting a short timer These storms have rarely occurred where precipitation could be m asured at a weather station. In the Manitou Springs area, the eak discharge from a cloudburst is greater than that caused by ainfall during a period of snowmelt. - Vegetation varies throughout the study area. In areas above the timberline~ vegetation is sparse. In the timber and woodland areas, aSPfn, oak brush, spruce, juniper, and native grasses are found. I ! The soils in the study consist mainly of sandy to clayey material with a high percentage of rock fragments. Rock outcropping occurs on approxi ately 40 percent of the area and consists mainly of crystallin and sedimentary rocks. The depth to the bedrock is usually sh llow. 2.3 Principal lood Problems I Manmade an~ natural obstructions in the flood plains impede the flow of wa~er, creating a backwater effect and increasing flood heights. these obstructions in Manitou Springs take the form of trees, ~rush, and numerous footbridges and planked crossings I throughout I the study area. This material is carried downstream to create ~ams at bridges and in areas where the channels are restricted I by building foundations and other forms of encroachment. I Severe flo~ding has occurred several times in Manitou Springs. In July l8S2, a cloudburst in the city caused flooding on Fountain Creek, Williams Canyon, and Ruxton Creek. A wall of water came down Willi~ms Canyon and flooded Fountain Creek and the lower part of Ru*ton Creek. Most-houses in the area sustained some I i i e 5 '....