8249

• UCREFRP Catalog Number: 8249
• Author: Modde, T., W. J. Miller and R. Anderson.
• Title: Determination of Habitat Availability, Habitat Use, and Flow Needs of Endangered Fished in the Yampa River Between August and October.
• USFW Year: 1999.
• USFW - Doc Type: Project #CAP-9,
• Copyright Material: NO

~
u

800

-+-1997, wettest
_ ...... _ 1920, 25%
~1967,med~n
~ 1919, 75%
~ 1934, driest

200

8/21

9/10

9/30
Date

10/20

11/9

11/29

Figure 2.3. Seasonal hydrographs for the driest (1934), 75% exceedance (1919), median (1967),
25% exceedance (1920), and wettest (1997) years recorded on the Yampa River, Maybell gage.

550.
500 ..--..
.
450 '.,
400
350
300
,-,
ol!l
CJ 250
-
Cll
~
l.o 200
~
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CJ
III
Q 150
100
50
0
Ol Ol Ol Co 2- tl tl
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:! ~ ~ Vl Vl 0 0
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N N
Date

.--50%1
,! i
i- '60%1
'-70%
1-,.. 80% I
!-90%1

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o
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Figure 2.4. Fall hydrograph for the Yampa River, Mayben gage showing percentile flows.

total annual depletions occur in the months of April, May and June. Natural flow was reduced by an
average of only 6% for those three months. The fall and winter months of October through March
accounted for 8% of the annual water diversions and natural flow was reduced by about 6%. Depletions
had the greatest impact during August and September, when natural flows for the 17-year period were

22