FLOOD03999

• County: Elbert
• Community: Elbert County
• Stream Name: Arkansas River
• Basin: Arkansas
• Title: Flood-Prone Areas in Elbert County
• Date: 1/1/1982
• Prepared For: State of Colorado
• Prepared By: USGS
• Floodplain - Doc Type: Floodplain Report/Masterplan

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The largest probable flood is difficult to define, but comparison
of the peak flow observed from a given drainage area puts past floods
into perspective. Crippen and Bue (1977. fig. 14, p. 13) described
max i mum peak discharges observed for the reg ion wh i ch ,j nc I udes eastern
Colorado. Crippen and Bue drew an envelope curve, part of which has
been reproduced in the graph below. Flood data for sites in and near
Elbert County are included in the table. McCain and "Jarrett (1976)
determined that the lOO-year flood values in eastern Colorado are a
function of drainage area and basin slope. A lOO-year flood-discharge
curve, computed using an average basin-slope value, has been added for
visual comparison with the envelope curve. Actual lOa-year discharge
values at a site may differ from those of the lOa-year curve shown.

The envelope curve does not represent a physical limit, but shows
the magnitude of some extremely rare events which have occurred. East
Bijou Creek, which drains the central part of Elbert County, produced
a peak discharge in 1965 near the Arapahoe-Elbert County 1 ine which
approached the envelope curve (site 9). In 1935, a 50-year flood was
measured at the same site.

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1.11965) DATA POINT AND SITE NUMBER-
NlITlber in parenthesis is year
peak flow occurred. See table

5

.911965).

Envelope curve IAfter
Crippen and Bua. 1977)

13(1965).
5.(1935)
5' (1965)

12.11935)
10'11935)
11965)
8119351 1211965)
11.(1965) ..

8.9.11935)
. (1965)
7119651

l00..year recurrence interval
(After McCain and Jarrett. 1976)

1.119651

4'(19651

1
0,1

100

500 1000

5 10 50
DRAINAGE AREA, IN SOlJARE MILES

0,5

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