ISFAPPC02212 ‎(2)‎

• Case Number: 00CW0107
• Stream Name: Oil Creek
• Watershed: Fourmile Creek
• Water Division: 2
• Water District: 12
• County: Teller
• Instream Flow App - Doc Type: Supplemental Data

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Instream Flow Recommendation(s)

I BLM's instream flow recommendation is for 1.80 cfs (May I - October 31) & 1.35 cfs
(November I - April 30) (see BLM letter in Appendix A),

Land Status Review

Upper Terminus
headwaters

Total Length
(miles)
7.5

nd Ownershi
% Public
60

La
% Private
40

Lower Terminus
Fourmile Creek

This segment is approximately 60% public land and 40 % private land, 50% of the public land is
managed by the BLM and 50% by the U,S. Forest Service (See Figure 1)

Biological Data

The BLM has conducted field surveys of the fishery resources on this stream and have found a
natural environment that can be preserved. As reported for this reach of stream in their
September 25, 1998, letter to the CWCB, "The stream environment has experienced historical
dredge mining activity but has made a remarkable recovery. Riparian vegetation has been fully
established along the creek, stabilizing both the banks and the stream channel. Substrate, water
quality and food supplies are good for salmonids. However, a paucity of pool habitat and lack of
cover in some reaches are limiting factors. In addition, the Pikes Peak Granite, which erodes
easily throughout this region, and from the nearby highway, has a tendency to fill pool habitat.
Therefore, maintaining adequate flows is important for scouring pools, and for preventing late
summer fish kills because of high stream temperatures. Fish surveys indicate that the reach
supports a self-sustaining population of brook trout." (see BLM Fishery Survey in Appendix B),

Field Survey Data

BLM and CWCB staff used the R2CROSS methodology to quantify the amount of water
required to preserve the natural environment to a reasonable degree. The R2CROSS method
requires that stream discharge and channel profIle data be collected in a riffle stream habitat type,
Riffles are most easily visualized, as the stream habitat type that would dry up first should the
streamflow cease, This type of hydraulic data collection consists of setting up a transect,
surveying the stream channel geometry and measuring the stream discharge, Appendix B
contains copies of the field data collected in regards to this proposed segment.

Biological Flow Recommendations

The CWCB staff relied upon the biological expertise of the cooperating agencies to interpret the
output from the R2CROSS data collected to develop the initial, biologic instream flow
recommendation, This initial recommendation is designed to address the unique biologic
requirements of each stream without regard to water availability, Three instream flow hydraulic
parameters, average depth, percent wetted perimeter and average velocity are used to develop
biologic instream flow recommendations. The CDOW has determined that by maintaining these
three hydraulic parameters at adequate levels across riffle habitat-types, aquatic habitat in pools
and runs will also be maintained for most life stages of fish and aquatic invertebrates (Nehring
1979; Espegren 1996).

For this segment of stream, two data sets were collected with the results shown in Table I below.
The two surveys are listed in the order of where they are located on the segment, starting from
the most upstream survey to the most downstream survey. Table I shows who collected the data
(Party), the date the data was collected (Date), the measured discharge at the time of the survey
(Q), the accuracy range of predicted flows based on Manning's Equation (240% and 40% of Q),