8106

• UCREFRP Catalog Number: 8106
• Author: Anderson, R. M.
• Title: Riverine Fish-Flow Investigations.
• USFW Year: 1998.
• USFW - Doc Type: Fort Collins, Colorado.
• Copyright Material: NO

Table 4-C. The mean and standard deviation of the inflection point flows (cfs) and
the inflection point flow for the 50, 70, 80 and 90 percentile runs for seven variables
at 13 pools.

Variable Mean Std.Dev. 50% 70% 80% 90%
Wetted Width (ft) 80.0 38.1 60 100 100 135
Average Depth (ft) 84.6 37.7 80 82 100 100
Change in Stage (ft) 85.0 26.6 80 100 100 100
WidthlDepth Ratio 73.8 45.6 70 82 110 142
Wetted Area (sq ft) 83.1 24.3 80 100 100 100
Average Velocity (ftIs) 126.9 23.9 125 125 135 150
Grand Mean 88.9 37.0

Habitat Characteristics of Inflection Point Flows

Tables 5-A, 5-B and 5-C give the values for the variables for mean of the

inflection points for rimes, runs and pools, respectively. The mean of the inflection point

!Ji!-

for stream width was the variable that was most similar between habitat types, and was

164 ft (at 83 cfs), 170 ft (at 87cfs) and 166 ft (at 80cfs), for rimes, runs and pools,

respectively. At flows of around 100 cfs, stream width for the three habitat types is

similar at 165 ft (Appendix Figure 1). However, the width/flow relationship is much

different between habitat types as flow drops below 100 cfs. Stream width decreases

rapidly on rimes and typically approaches zero at zero flow (Appendix I, Figure 1). On

the runs, stream width decreases to 80 ft at 1 cfs and stream width is maintained at nearly

150 ft on pools at 1 cfs (Appendix I, Figures 1).

Even though inflection points for stream widths were similar for the three habitat

types, the percent of the channel that is wetted (wetted perimeter) at those widths

20