FLOOD10942

• County: Statewide
• Basin: Statewide
• Title: Colorado Water Conservation Board - 2001 Colorado Flood Documentation Report
• Floodplain - Doc Type: Flood Documentation Report

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Colorado Springs

The Fountain Creek watershed, shown on Figure 2.1-3, is a 927-square mile watershed that
drains south into the Arkansas River at Pueblo. The watershed is bordered by the Palmer Divide
to the north, Pikes Peak to the west, and a minor divide 20 miles east of Colorado Springs.

Figure 2.1-3
Fountain Creek Watershed

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2.2 STORM EVENT DATA

2.2.1 Precipitation Data

Mr. Bruce Thorson, an engineer with the City of Colorado Springs, reported a rainfall total of
approximately 5.4 inches at Colorado College; most of the precipitation fell in an 8-hour period
from 11 A.M. to 7 P.M. Smaller amounts of rain fell at locations south of the city: 0.41 inches at
Pinello Ranch, and 0.27 inches at the Nixon Power Plant.

A NOAA Event Record indicates that more than 5 inches fell in approximately 5 hours. The
NOAA web site (http://precip.fsl.noaa.gov/hourly ~recip.htm containing "raw" data, which has
not undergone Quality Control) does not contain a gage station near downtown Colorado
Springs, and it does not indicate that more than 0.6 inches fell on this date at any of the gage sites
near Colorado Springs (e.g., in Manitou Springs, near Fountain Creek and Janitell Road). This
indicates that the intense storm was very localized around the downtown area.

A comparison between the Event Record data and precipitation-duration-frequency curves
(Figure 2.2-1 developed from the u.S. Department of Commerce, NOAA Atlas 2, Volume 111-
Colorado) indicates that the localized precipitation that occurred in the downtown area is
equivalent to a much greater than a 100-year frequency event.

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