FLOOD10854 ‎(2)‎

• Designation Number: 590
• County: Denver
• Community: Denver
• Title: FIS - Denver - Volume 1
• Date: 11/17/2005
• Prepared For: Denver
• Prepared By: FEMA
• Floodplain - Doc Type: Current FEMA Regulatory Floodplain Information

2.3 Principal Flood Problems

Past flooding along most of the streams in Denver has been well documented in
several reports by the USACE and the UDFCD.

Large floods have been reported on the South Platte River in 1844, 1864, 1867, 1876,
1894,1921,1933,1942, 1965, and 1973. The Largest and most damaging of these
occurred June 16 and 17, 1965, when a discharge of 40,300 cubic feet per second...
(cfs) was computed at U.S. Geological Survey stream gage No. 06714000 near the
19th Street bridge in Denver. Flooding occurred throughout the South Platte River
Basin with six persons drowned, two other deaths caused by flood-related activities,
and estimated damages of $500 million, of which $300 million occurred in the
Denver area (References 3-7).

Past floods on Clear Creek in the Denver area have been infrequent and usually not
severe in the lower reaches. The major flooding has occurred upstream from Denver,
including the City of Golden in 1888 (8,700 cfs) and 1956 (5,250 cfs), and Derby in
1965 (5,070 cfs) (Reference 8).

Flooding has occurred along Bear Creek in 1876, 1894, 1896, 1957, 1965, and 1969.
The 1896 flood was the largest experienced, with 27 lives lost and severe property
damage reported from the Town of Evergreen to the mouth. The discharge at the
Town of Morrison gaging station was 8,600 cfs (Reference 9).

Prior to the construction of C'herry Creek Dam, major floods occurred on
Cherry Creek in 1864, 1885, 1912, and 1933. Both the 1912 and 1933 floods were
reported to have resulted in damages of approximately $1 million (Reference 10).
Construction of Cherry Creek Dam was completed in 1950, and the dam is estimated
to have prevented considerable damage during the flood of June 1965.

From 1942 to the present, there have been at least 14 years with major flooding
events from Cherry Creek, during which flooding of premises and impedance of
traffic occurred. Flood-causing rainfall in these years produced overland inundation
of homes and streets to depths of as much as 4.5 feet. Floodflows in this area
(north of Lowry Air Force Base) for these storm events were in the range of
300 to 600 cfs. From 1942 through the early 1960s, flooding problems were
confined to areas downstream of Lowry Air Force Base. Since approximately 1965,
rainfall flood events have begun to occur in the upper watershed as a direct result of
the increasing density of development (Reference 11).

For Dry Gulch (Lakewood Gulch Tributary), there are no accurate records of flood-
history available; however, it is well known that there have been numerous instances
of minor damage occurring at several locations along the stream (Reference 12).

Prior to 1965, Harvard Gulch experienced regular flooding due to summer
thunderstorms. Considerable encroachment of the floodplain and channel occurred
because of the lack of city zoning designed to prevent such encroachment. The
infringement on the channel was so complete that the defined channel ended

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