BOARD00048 ‎(2)‎

• Board Meeting Date: 9/19/2006
• Description: ISF Section - Contested Instream Flow Appropriation Hearing - Elkhead and Armstrong Creeks
• Board Meetings - Doc Type: Hearings

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. 45.4 square miles (See Gage Summary in Appendix C). The total drainage area of this segment
of the Annstrong Creek is approximately 3.54 square miles. The period of record for this gage
was 1942 to 1973, the period of record used by staff in their analysis was 1942 - 1973, or 19
years of record. Table 2 below displays the estimated flow of Armstrong Creek at the gage, in
terms of a percentage of exceedence.

T.ble 1: Ubrnaled SlrClIm Flow for AnnItrona C,"k
Exctedence Jan Feb Mar Apr
1-/. 0.50 0.39 1.44 31.19
S% 0.40 0.39 0.78 22.46
10% 0.34 0.34 0.60 14.04
20-;. 0.31 0.31 0.47 7.80
soe;. 0.25 0.2.1 0.30 2.J4
80'"1. 0.17 0.19 0.23 0.86
90% 0.14 0.17 0.20 0.43
9~W. 0.14 0.12 0.17 0.31
9'9% 0.14 0.12 0.16 0.20

1\11>'
48.36
40.20
35_82
28.04
15.75
8.89
6.99
5.13
3.34

J..
26.99
17.15
15.28
10.92
4.44
2.11
L2S
0.94
0.50

Jul Aug Sep Oct
2.71 0.91 l.01 0.86
2.03 0.64 0.63 0.69
1.72 0.54 0.44 0.62
1.33 0.40 0.36 0.51
0.71 0.26 0.22 0.30
0.30 0.14 0.11 0.18
0.22 0.08 0.07 0.16
0.15 0.05 0.05 0.15
0.10 0.03 0.05 0.07

Estimated Stream Flow on Armstrong Creek

6.00
. 5.00
4.00
" 3,00
-
u
2_00
1.00 - -
0.00

No\' DK
0.78 0.59
0.64 0.50
0.58 0.39
0.44 0.37
0.31 0.27
0.22 0.17
0.19 0.16
0.18 0.14
0.16 0.14

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dee
Month

Table 2 shows that the summer flow recommendation of 1.0 cfs is available at least 50% of the
time for the month of April 1'" through July 15th. The winter flow recommendation of 0.4 cfs is
not available at least 50% of the time from July 16th through March 31.... Based on water
availability, the winter recommendation was further reduced to 0.25 cfs for the time period of
July 16" through March 31'_

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