ISFAPPC04246

• Case Number: 00CW0101
• Stream Name: Fourmile Creek
• Watershed: Fourmile Creek
• Water Division: 2
• Water District: 12
• County: Fremont
• Instream Flow App - Doc Type: Supplemental Data

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j' Executive Sununary

I The City of Cripple Creek and the Cripple Creek/Victor Mining Company objects to the ISF
ri recommendations for the four segments of 4 Mile Creek (24.6 miles) proposed by the Colorado
. Water Conservation Board The objectors engaged W. W. Wheeler and Associates and Queen of
the River Fisheries Consultants to review the proposed ISF filings, methodologies used to develop
the recommendations, develop an expanded database which describes the stream, and to develop'
I recommendations based on the database. Objectors consultants completed a thorough review of
the proposed ISF filings and elected to complete 9 additional R2 Cross cross sections on the
stream longitudinally distributedfrom Reach #3 below Barnard Creek to Reach #O,S above Wilson
I Creek. Sampling points in 1998 were distributed to provide 3 cross sections for modeling and
review of flow recommendations within each reach. The analysis combined the 3 (1996) BLM
I sample points with the objectors additional 9{ 1998) sample points to achieve this study design
criteria. Only 11 cross sections were evaluated (Table 2) because the analysis of the BLM Reach 3
sample point was not included in the ISF #9S/2/A-023 packet provided The objectors effort
I emphasized field observation of at least 60% of the channel length in question on 4 Mile Creek
and representativeness of cross sections measured Objectors consultants completed field
reconnaissance of approximately IS,S miles of stream. Each cross section measured was
I identified by averaging the grassline widths of 2-3 adjacent riffles and placing the measurement
effort at the grassline width that was closest to the mean width measured Minimum flow
recommendations for each reach were based on the mean criteria for all cross sections measured
I in the reach. Minimumflow criteriafor the protection of the natural environment to a reasonable
degree was established based on Nehring (1979) and CWCB(1996) with velocity criteriafor
summer flows adjusted to 0.8 ft/sec as proposed by the CWCB in the ISF initial filings documents.

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The results of this effort illustrate that 2 BLM sample points chosen based on the R2 Cross
methodology for site selection that are distributed only on public land does not provide as
accurate an understanding of the influences of flow recommendations on 4 Mile Creek as 11 cross
sections longitudinally distributed in the watershed and stratified to assure'average grassline
width cross sections were measured Understanding of the mean criteria responses for 2-3
representative cross sections per reach provides more information for decision makers regarding
influences of flow recommendations on 4 Mile Creek, especially in Reach # 1 where no data was
collected at all for the proposed ISF recommendations, The data base developed and analyzed
illustrates that changes to the proposed ISF flow recommendations are justified as follows:

CWCB Flow Recommendations
R#3 6.0 cfs{S/I-7/31)
R#2 7.0 cfs{S/I-7/31)
R#1 13,0 cfs{4/1-6/30)
R#O,S 7.S cfs{S/I-10/31)
Alternative Flow Recommendations
R#3 4.2S cfs{S/I-7/31)
R#2 6.0 cfs{S/I-7/31)
R#1 6,0 cfs{4/1-7/31)
R#O,S S.2S cfs{S/I-10/31)

3,0 cfs{8/1-10/31)
4.0 cfs{8/1-10/31
7,S cfs(7/1-7/31)
4.S cfs(II/I-4/30)

2,S cfs(11/1-4/30)
2.S cfs{II/I-4/30)
4,S cfs(8/1-3/31)

3.0 cfs(11/1-4/30)
4.0 cfs(8/1-10/31)
4.2S cfs{8/1-3/31)
3.0 cfs(II/1-4/30)

2.S cfs(11/1-4/30)