FLOOD00457

• County: El Paso
• Community: Colorado Springs and Manitou Springs
• Title: Paleohydrologic Flood Investigations for Streams in Manitou Springs and Colorado Springs
• Date: 12/3/1987
• Floodplain - Doc Type: Flood Documentation Report

specifically for the Colorado and Manitou Springs area. Notes and
field maps are on file in the Colorado District office. In Cook Creek
(Butler Canyon) just north of Palmer Lake evidence of significant
flooding ends at about 7,900 feet. In an unnamed tributary to
Carpenter Creek, just south of Cook Creek. evidence of significant
flooding ends at about 7,750 feet. In North Monument Creek and its
foothill tributaries, there are flood deposits in the channel up to
the Lower Reservoir at an elevation of 7,500 feet. Because the Lower
and Upper Reservoirs could have an effect on flood deposits, earlier
investigations were made in Monument Creek and tributaries upstream
from the reservoirs. There was no evidence of significant out of bank
flows.

REVIEW OF LARGEST FLOODS IN EL PASO COUNTY AND VICINITY

Historic, streamflow-gaging station, and miscellaneous flood
records were reviewed to determine the largest floods and to define an
elevation limit to significant rainfall runoff in EI Paso County. The
primary sources for historic flood information are in Follansbee and
Sawyer (1948) and the two flood-plain information reports for Fountain
Creek (U.S. Army Corps of Engineers, 1974; U.S. Federal Emergency
Management Administration, 1983). These reports indicate that there
have been several flash floods in Manitou Springs in the past 100
years. In 1882 a cloudburst caused flooding on Williams Canyon, lower
Ruxton Creek, and Fountain Creek. In 1894 heavy rain caused lesser
flood~ng on the same creeks. In 1947 a flash flood occurred on
Williams and Waldo Canyons. The discharges associated with these
floods can not be determined from the reports (and is one reason for
the paleoflood investigations). However, it appears that the 1882
flood was the largest. All flood reports indicate changing channel
capacity with time and that channel obstructions (particularly bridges
and culverts) cause flood depths to be locally higher and cause water
to flow down streets making the floods appear larger. It must be
recognized that when bridges were washed out in these historic floods
they generally were much lower in the channel. Also, in many cases,
these were wooden bridges (logs with planks) across the low-water
channel; hence, were suseptible to washout with even small floods.
The maximum flow recorded at streamflow-gaging stations and the
maximum indir~ctly measured floods (when streamflow conditions
preclude direct measurement of floods) in El Paso County were
summarized. Also copies of streamflow records collected by the
Southern Colorado Power Company, generally from 1905 to 1950, were
available in discontinued station files in the Colorado District
office were reviewed and summarized (several. of these records were
summarized monthly flows and could not be used to determine the peak
flow). A list of all Colorado streamflow-gaging stations is provided
which shows the period of record for each station. Also included are
the indirect discharge measurements available in El Paso County.
These streamflow records are provided as an attachment. The maximum
streamflow for these locations are summarized graphically in Figures 3
and 4. Both these graphs show that the magnitude of floods decrease

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