ISFAPPC01684

• Case Number: 03CW0036
• Stream Name: Eaglebrook Creek
• Watershed: Rock Creek
• Water Division: 3
• Water District: 25
• County: Saguache
• Instream Flow App - Doc Type: Supplemental Data

Hydrologic Data

After receiving the cooperating agency's 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 hydro graph below was derived from data collected by the
USGS stream gage for Raspberry Creek near Villa Grove, CO (ill #08224200), which has a
drainage area of 1.8 square miles (See Gage Summary in Appendix C). The total drainage area
of the Eaglebrook Creek Drainage is approximately 2.0 square miles. The period of record for
this gage was 1967 to 1970, the period of record used by staff in their analysis was 1967 - 1970,
or 4 years of record. Table 2 below displays the estimated stream flow of Eaglebrook Creek, in
terms of a percentage of exceedence.

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Table 2: Estimated Eaglebrook Stream Flow at Rock Creek.
Exceedences Janua Februa March ," M. June Jill Au ust Se tember October November December
1% 0.65 0.60 0.79 1.33 3.35 2.58 1.44 1.66 1.33 0.99 0.83 0.65
5% 0.63 0.56 0.67 0.88 2.63 2.13 1.35 1." 1.24 0.96 0.82 0.64
10% 0.61 0.54 0.67 0.87 2.13 1.91 U4 1.35 1.12 0.96 0.79 0.83
20% 0.56 0.46 0." 0.58 1.80 1.69 1.12 1.24 1.07 0.92 0.74 0.61
50% 0.34 OAO 0.45 0.45 0.92 1.35 0.79 0.96 0.96 0.89 0.63 0.40
80% 0.22 0.34 0.35 0.37 0.47 0.47 0.62 0.63 0.70 0.70 0.51 0.20
90% 0.22 0.34 0.31 0.34 0.34 0.30 0.39 0.55 0.87 0.66 0.47 0.13
95% 0.22 0.33 0.31 0.34 0.34 0.37 0.37 0.51 0.66 0.66 0.44 0.11
99% 0.22 0.22 0.29 0.33 0.25 0.35 0.35 0.48 0.63 0.63 0.39 0,09

Eaglebrook Creek Estimated Stream Flow

1.4
1.2
1
-t 0.8
0.6
0.4
0.2
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Month

Table 2 shows that the summer flow recommendation of 1.4 cfs is not available at least 50% of
the time during any month. The summer flow recommendation was further reduced to 0.75 cfs
for the time period of May 15th through October 31 st based on limited water availability. Table 2
also shows that the winter flow recommendation of 0.5 cfs is only available at least 50% of the
time from November 1st through November 30th. The winter flow recommendation was further
reduced to 0.35 cfs for the time period of December 1st through May 14th based on limited water
availability.

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