BOARD02512

• Board Meeting Date: 1/27/2004
• Description: ISF Section - Instream Flow Appropriations - Fourmile Creek
• Board Meetings - Doc Type: Memo

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 Chalk Creek near St. Elmo, CO (ID #07090000), which has a drainage
area of 48 square miles (See Gage Summary in Appendix C). The total drainage area of the
Fourmile Creek Drainage is approximately 38.0 square miles. The total drainage area of
Fourmile Creek upstream of Little Fourmile Creek is 15.3 square miles. The period of record for
this gage was 1913-1919, the period of record used by staff in their analysis was 1913-1919, or 6
years of record. Table 2 below displays the estimated stream flow of Fourmile Creek, in terms
of a percentage of exceedence.

Table 2: Estimated Founnile Creek streamflow at Little Founnile Creek.

Exceedences
1%
5%
10%
20%
50%
80%
90%
95%
99%

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Januarv Februarv March ADril Mav June Julv Auaust SeDtember October November December
3.87 3.29 9.88 28.05 90.49 137.45 88.58 37.29 20.59 10.20 6.82 5.14
3.83 3.19 4.69 15.94 77.81 125.91 69.49 28.69 14.66 8.83 6.38 4.14
3.83 3.19 3.83 10.84 67.96 114.43 53.36 25.63 12.75 8.29 5.42 4.14
3.19 2.90 3.19 7.97 52.53 99.13 45.58 20.72 10.52 7.65 4.78 3.83
2.55 2.55 2.87 4.46 27.41 65.03 32.83 13.07 7.65 5.74 3.83 3.19
2.55 2.23 2.55 3.51 14.73 45.58 20.72 8.93 6.38 4.85 3.19 2.93
2.55 2.23 2.55 3.19 7.33 37.61 16.19 8.29 5.10 4.46 2.87 2.87
2.55 2.23 2.55 2.87 6.47 32.51 14.66 7.65 4.78 4.14 2.55 2.87
2.23 2.23 2.23 2.55 5.74 27.41 9.94 6.97 4.46 3.83 2.49 2.87

Fourmile Creek Estimated Stream Flow

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Table 3: Estimated Founnile Creek streamflow upstream of the Arkansas River.

Exceedences
1%
5%
10%
20%
50%
80%
90%
95%
99%

Januarv Februarv March ADril Mav June Julv Auaust SeDtember October November December
9.61 8.16 24.54 69.67 224.75 341.37 220.00 92.63 51.14 25.33 16.94 12.78
9.50 7.92 11.64 39.58 193.25 312.71 172.58 71.25 36.42 21.93 15.83 10.29
9.50 7.92 9.50 26.92 168.78 284.21 132.53 63.65 31.67 20.58 13.46 10.29
7.92 7.20 7.92 19.79 130.47 246.21 113.21 51.46 26.13 19.00 11.88 9.50
6.33 6.33 7.13 11.08 68.08 161.50 81.54 32.46 19.00 14.25 9.50 7.92
6.33 5.54 6.33 8.71 36.58 113.21 51.46 22.17 15.83 12.03 7.92 7.28
6.33 5.54 6.33 7.92 18.21 93.42 40.22 20.58 12.67 11.08 7.13 7.13
6.33 5.54 6.33 7.13 16.07 80.75 36.42 19.00 11.88 10.29 6.33 7.13
5.54 5.54 5.54 6.33 14.25 68.08 24.68 17.31 11.08 9.50 6.18 7.13

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