8232

• UCREFRP Catalog Number: 8232
• Author: Burdick, B. D.
• Title: Evaluation of Fish Passage at the Grand Valley Irrigation Company Diversion Dam on the Colorado River Near Palisade, Colorado.
• USFW Year: 1999.
• USFW - Doc Type: CAP-17,
• Copyright Material: NO

period following marking, it was assumed that this fish used the newly-
constructed notch for passing by the diversion dam (Figure 3). During this 8-day
period, flows measured at the Palisade USGS streamflow gage approximately 0.4
mile downstream from the diversion dam ranged from 1,300 cfs on the 19 and 20 of
August to 1,580 cfs on the 22 and 23 of August.
Forty native and six nonnative fish were recaptured downstream of the
diversion dam. This was 2.5i of the total number of all fish either PIT tagged,
floy tagged, or fin clipped. Of the 1,128 non-endangered native fishes
(flannelmouth and bluehead sucker, and roundtail chub) that were PIT tagged, 31
were recaptured downstream of the diversion dam, a 2.7i recapture rate. Twenty-
seven flannelmouth sucker were recaptured along with nine bluehead sucker, and
four roundtail chub. Of the 40 native fish that were recaptured, 31 had been PIT
tagged and nine had been fin clipped. The recapture rate for the number of
native fish PIT tagged (1,128; 2.7%) was slightly higher than the number of
native fish that had been fin clipped (470; 1.9i). Of 203 carp and white sucker
initially floy tagged, three carp and three white sucker were recaptured (3.Oi
recapture rate). None of the two rainbow trout, 18 brown trout, or 28 hybrid
sucker marked were recaptured.
Twelve species and three hybrids (Catostomidae) were collected during this
study (Appendix Table A.l.). Twenty-seven channel catfish were caught during the
1-year study; seven were collected upstream of the GVIC Diversion Dam. Sixty-one
mountain whitefish were collected--50 upstream of the diversion dam. Five sub-
adult smallmouth bass and one sub-adult largemouth bass were also collected.
During a similar 7-month study to determine if a grade-control structure
constructed on the Yampa River near Craig, Colorado, would impede movements of
Colorado pikeminnow, Masslich (1993) reported that native and nonnative fishes
moved both up- and downstream through aman-made notch composed of varying sizes
of boulders and cement. He used mark and recapture techniques similar to those
used in this study. He reported 25 fish representing two species of native
fishes (flannelmouth sucker and bluehead sucker) that had been PIT tagged and
three species of nonnative fishes (northern pike, white sucker, and smallmouth
bass) that had been Floy~ tagged moved either up- or downstream through this
notch created to pass fish.
Masslich (1993) PIT tagged 249 native fish
fish. He reported recapture rates much higher
GVIC evaluation. Of 1,344 fish tagged during his
tagged fish and 23 fish that had been PIT tagge
19.71.
Endangered Fish
Captures
and F1 oy°~ tagged 1, 095 nonnative
than those reported during the
study, he recaptured 242 Fl oy -
d for an overall capture rate of
Nineteen adult Colorado pikeminnow were captured during this evaluation
(Appendix Table D.1.). Ten of these were captured upstream of the GVIC Diversion
Dam between 19 August and 24 September. However, it is unknown whether these
fish used the newly-constructed fish passage notch at the diversion dam or si mpl y
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