BOARD01130

• Board Meeting Date: 1/26/2000
• Description: ISF Section - Instream Flow Appropriations - Water Division 5
• Board Meetings - Doc Type: Memo

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c Table 1: Data

Party Date Q 250%-40% Summer (3/3) Winter (2/3)
BLM 7/9/98 3.15 7.9-1.3 5.2 1.3

BLM = Bureau of Land Management (1) Predicted flow outside of the accuracy range of Manning's Equation.
? = Criteria never met in R1CROSS Staging Table.

Biologic Flow Recommendations
The BLM recommended a 5.1 and 1.7 cfs summer flow and a 1.0 cfs winter flow based on their
July 9th, 1998, data collection effort and their water availability analysis. Staff has reviewed the
data collected by the BLM. The summer flow recommendation, which meets 3 of 3 criteria and
is within the accuracy range of the R2CROSS model, is 5.2 cfs. The winter flow
recommendation, which meets 2 of 3 criteria and is within the accuracy of the R2CROSS model,
is 1.3 cfs.

Hydrologic Data

After receiving the cooperating agencies' biologic recommendation, the CWCB staff conducted
an evaluation of the stream hydrology to determine if water was physically available for an
instream flow appropriation. The hydrograph was derived from data collected by the USGS
stream gage for Northwater Creek near Anvil Points (ID #09092830), which has a drainage area
of 12.6 square miles (see Gage Summary in Appendix C). The period of record for this gage is
1976 to 1983, the period of record used by staff in their analysis was 1976-1983, or seven years
of record. The estimated drainage area of Northwater Creek downstream and including
Raspberry Creek is approximately 7.6 square miles. Tables 2 and 3 below display the estimated
flow of Northwater Creek at the confluence with Raspberry and Trapper Creeks, in terms of a
percentage of exceedence. The orange and blue shading highlights how often the summer and
winter flow recommendations have been available.

Table 2: Northwater Creek downstream of Raspberry Creek

Exceedences January February March April May June July August September October November December
1% 0.48 0.52 1.66 ",":l~;$fYt m;iHJ>'S!lIl1 . 2.23 1.39 1.10 LlO 0.66 0.66
5% 0.36 0.45 Ll5 tJiJl1~ ~,.,moo12521 1.99 1.21 0.66 0.72 0.60 0.61
10% 0.33 0.40 0,86 ":raC~~i;1~~ 1.81 Ll5 0.60 0.72 0.57 0.54
20% 0.33 0.36 0.72 ",Jl,~ I~~' 4.52 1.69 1.03 0.53 0,58 0.51 0.39
50% 0,27 0.31 0.52 1.63, . . 2.41 . Ll5 0,72 0.45 0.45 0.39 0.30
80% 0.18 0.18 0,30 0.72 1.03 0.54 0.45 0.23 0.27 0,29 0.27 0.22
90% 0.14 0.14 0.20 0.60 0.66 0,27 0,12 0,19 0.24 0,22 0,16 0.15
95% 0.14 0.14 0.14 0.45 0.33 0.21 0,10 0.03 0.19 0,19 0,15 0.15
99% 0,14 0.12 0.13 0.38 0.27 0.19 0.03 0.02 0.19 0.14 0,13 0,15

Table 3:Northwater Creek upstream of Trappers Creek
Exceedences Januar Febro March A ril Ma June Jul Au ust Se tember October November December
1% 0.80 0.86 2.75 \'t5b~~;?i~ i!i2'8':'d. 3.70 2.31 1.82 1.83 1.10 1.10
5% 0,60 0.74 1.91 .'!~9IOOC OO-~> 3.30 2.00 LlO 1.20 1.00 1.01
.~
10% 0.55 0.67 1.43 ::Ii2i:iJ(if' 6f13t 3.00 1.90 0.99 1.20 0,95 0,90
20% 0.54 0.60 1.20 iiij!l00K . 2.80 1.70 0.88 0,97 0.85 0.64
50% 0.45 0.52 0.86 2.70 Z:z . 1.90 1.20 0.74 0,75 0,65 0,50
80% 0,30 0.30 0.50 1.20 1.70 0.75 0.39 0.45 0.48 0.45 0.37
90% 0.23 0.23 0,33 1.00 1.10 0,20 0,31 0.40 0,37 0.26 0.25
95% 0.23 0.23 0.23 0.74 0.55 0.17 0.05 0.32 0.32 0,25 0.25
99% 0.23 0.20 0.22 0.63 0.45 0,05 0,03 0.32 0.23 0.22 0.25

Tables 2 and 3 show that the summer recommendation of 5.2 cfs is available 50% of the time for
the month of May and 10% of the time in April and June throughout the entire reach. Tables 2
and 3 also show that the winter recommendation of 1.3 cfs is only available 1 % of the time in the
month of March throughout the entire reach. Based on the above water availability analysis and
the requirement of the CWCB staff to balance the needs of mankind with a reasonable