8178

• UCREFRP Catalog Number: 8178
• Author: Anderson, R. and G. Stewart.
• Title: Riverine Fish Flow Investigations.
• USFW Year: 1999.
• USFW - Doc Type: Fort Collins, CO.
• Copyright Material: NO

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
1

At 200 cfs Sevens had double the percent of surface area at intermediate (2.5 to
3.5 ft) depths with about 12% of the area (Figure 3, and Figure AJ.6). At flows of 50,
100 and 150 cfs the percent of area in the depth range of2.5 to 3.5 feet was about 10%
at Sevens compared to 5% at Duffy.

50%
45%
400k
lI:l 35%
e
c:(
'C 30%
Q)
:::
~ 25%
-
c 20%
Q)
u
~
Q)
11. 15%
10%
5%
0%
0 1

Flow of 200 cfs

2

3

4

5

6

7

8

9

10

Depth in feet

Figure 3. Percent of wetted area for depths at a flow of 200 cfs for the DutTy
and Sevens study sites.

In the depth range between 3.5 to 5.5 ft Sevens and Duffy had similar areas (6%)
at 200 cfs (Figure 3 and Figure AJ.7). However at flows less than 200 cfs, area dropped
quickly to just below 2% at Sevens but remained at 6% for Duffy (Figure AJ. 7). Sevens
had very little area with depths over 5.5 ft (0.1%) at flows of 50, 100 and 150 cfs while
Duffy had about 2% at depths over 5.5 feet between 50 and 200 cfs (Figure AJ.8). This
data indicated that even at very low flows, the Duffy station still maintains deep pool
habitat, while deep pools are lost at the Sevens station.

18