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

dam or simply passed over the diversion structure when it was inundated during
spring runoff. Eight of the ten fish captured upstream of the diversion dam had
been initially captured and PIT tagged downstream of the diversion dam either
sometime prior to- or during the 1998 runoff. Five of these eight fish were last
captured downstream of the diversion dam in 1998 between 23 April and 11 June,
one was captured in June 1997, one in April 1993, and one in June 1991.
This is not the first time that Colorado pikeminnow have been reported
upstream of the GVIC Diversion Dam. The U. S. Fish and Wildlife Service
(Osmundson and Kaeding 1989) documented a radio-tagged adult Colorado pikeminnow
moving upstream to the GVIC Diversion Dam in mid-July 1986. The fish eventually
passed the structure and moved upstream to the base of the Price-Stubb Dam. This
fish either moved upstream over the GVIC Diversion or could have passed around
the diversion dam via the Orchard Mesa Irrigation Diversion (OMID) bypass canal.
Flows at this time were approximately between 5,700 and 7,600 cfs over the GVIC
Diversion Dam, therefore it is suspected this fish may have passed around the
structure via the bypass canal. This fish remained until late-September when it
returned downstream and passed either over or around the diversion dam (via the
OMID bypass canal or through the GVIC flood gates). The same fish returned to
the base of the GVIC Diversion Dam in late-July 1987 and progressed upstream to
the base of Price-Stubb Dam. It remained there until mid-September 1987, when
it again made its way downstream, passing the GVIC Diversion.
Valdez et al. (1982) sampled the Upper Colorado River between Palisade and
Debeque, Colorado (RM 210), between 1979-1981. Most of their sampling occurred
upstream of the Government Highline Diversion Dam but they did sample the river
reach between Government Highline and Price-Stubb Diversion dams once each during
July 1979 and April 1980. They reported collecting six native and four nonnative
fish species with electrofishing, fyke nets, gill nets, and seines. Valdez
(1984) sampled the Upper Colorado River between Government Highline Diversion and
the Price-Stubb dams with electrofishing, seines, dip nets, and drift nets
between April and September 1984. During this same period, he sampled the Upper
Colorado River between the Price-Stubb and GVIC Diversion dams, but only
sparingly with seines. Valdez did not collect any Colorado pikeminnow during any
of these investigations. Kidd (1982) caught sub-adult Colorado pikeminnow
(number unknown) in a backwater immediately downstream of the GVIC Diversion Dam
in the spring and early-summer of 1980. According to Kidd (personal
communication), this backwater is synonymous with the location of the present
series of pools and riffles that were constructed for fish passage i n 1998 at the
GVIC Diversion Dam.
Telemetry
Two adult Colorado pikeminnow were implanted with LOTEK~ transmitters in
mid-April, one approximately 2 miles downstream of the diversion dam and the
other approximately 4 miles downstream. However, neither these two or any other
pikeminnow that had active LOTEK" transmitters associated with other ongoing
studies were detected moving through or downstream of the GVIC Diversion Dam by
the automated LOTEK~ data-logging station that had been deployed at the diversion
dam in early-April.
11