BOARD00970

• Board Meeting Date: 7/22/1993
• Description: Agenda or Table of Contents, Minutes, Memos. Partial.
• Board Meetings - Doc Type: Meeting

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INSTREAM FLOW QUANTIFICATION - LITTLE DRY CREEK
April 5, 1993
PAGE 7

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important to the species of fish utilized in the PHABSlM portion of the modeling.

The habitat suitability (HSl) curves that were used for the three species of fish described
above were obtained from the US Fish and Wildlife Service's Fort Collins, Colorado office, the
National Ecology Research Center. The HSI curves are depicted in Figure 2, 3, and 4. The
sources for these HSI curves are found in the references section of this report. HSI curves for
fathead minnows (adults only), creek chubs (adults and juveniles), and white suckers (spawning,
fry, juveniles, and adult life stages) were selected for use in this study. The following
discussion relies upon the PHABSlM results from these HSI curves.

IFIMIPHABSIM RESULTS

As stated above, two IFlM representative reach study sites were selected from the habitat
survey of the entire reach of Little Dry Creek throughout CGV and CRY. Transects were
selected to describe pools, runs, and riffles typical and representative of the Little Dry Creek
corridor. The CRY site had six cross sections and the CGV site had five cross sections. Field
measurements were collected per the IFlM methodology. The field information was assembled
into data files and the hydraulic calibration and simulation phases of the methodology was
completed without incident. The PHABSlM portion of the IFlM methodology was then
completed and the results analyzed by the DOW.

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Since the flows in Little Dry Creek are fairly low and quite steady, habitat was simulated
at flows ranging from 0.5 to 5 cfs. This range of flows is typical for Little Dry Creek and is,
for the most part, within the accepted band of confidence for the hydraulic simulation. The
results of the PHABSlM analysis is displayed in Table 1 and Table 2 and Figure 5 and Figure
6.

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