9513

• UCREFRP Catalog Number: 9513
• Author: Kuhn, G. and C. A. Williams.
• Title: Evaluation of Streamflow Losses Along the Gunnison River from Whitewater Downstream to the Redlands Canal Diversion Dam, near Grand Junction Colorado, Water Years 1995-2003.
• USFW Year: 2004.
• USFW - Doc Type: Reston, VA.
• Copyright Material: NO

Evaluation of Streamflow Losses Along the Gunnison River from Whitewater Downstream to the Redlands Canal Diversion
Dam, near Grand Junction, Colorado, Water Years 1995-2003
Table 1. Streamflow-gaging stations and miscellaneous discharge-measurement sites along the Gunnison River study reach.
[--, not applicable; USGS, U.S. Geological Survey; ND, not determined; CDWR, Colorado Division of Water Resources; RPWA, Redlands Power and
Water Authority]
Station or site
name as used
in this report
(figure 1)

Complete station name Distance
downstream
from White-
water station
(river miles) Drainage
area
(square
miles)
Operating
agency Period of
discharge
record
(water year)
Streamflow-gaging stations
Whitewater station Station 09152500 Gunnison River near Grand -- 7,928 USGS 1897-98;
Junction 1902-06;
1916-2003
Below-Redlands-dam station Station GUNREDCO Gunnison River below 12.64 ND CDWR 1995-20031
Redlands Canal diversion dam
Redlands-Canal station Station RLCGRJCO Redlands Canal near 12.52 -- CDWR 1975-2003
Grand Junction
Miscellaneous discharge-measurement sites
Ml -- 3.10 ND -- --
M2 -- 5.68 ND -- --
M3 -- 7.89 ND -- --
M4 -- 9.92 ND -- --
Othersite
-- Redlands Canal diversion dam 11.83 -- RPWA --
1Station is operated only as a real-time station for purposes of water-rights administration and water-resources management
No historical daily mean discharge records are available.
study described in this report, it also was assumed that there
were no Streamflow losses from the diversion dam downstream
to the two stations. Streamflow losses were investigated directly
(by making discharge measurements) for discharges of about
600 and 2,000 ft3/s, and indirectly (by analysis of historical dis-
charge records) for the complete range of discharges recorded
along the study reach.
Prior to making the discharge measurements along the
study reach, two reconnaissance trips were made during
January 2003 to evaluate the geologic, hydrologic, and physical
characteristics of the study reach and to select intermediate
measuring sites between the upstream and downstream gaging
stations. Four intermediate sites (M1, M2, M3, and M4; fig. 1,
table 1) were selected for discharge measurements in addition
to the current stations. Originally, five sets of discharge mea-
surements were proposed to be made, but because of the results
of the first two sets (described later in this report), it was deter-
mined that the additional measurement sets were not needed.
Although Streamflow transit losses along the Gunnison
River for Recovery Program releases from the Aspinall Storage
Unit eventually might require investigation from the release
point downstream to the Redlands Canal diversion dam, the
scope of the current study was limited to the reach from the
Whitewater station downstream to the Redlands Canal diver-
sion dam. Estimation of Streamflow transit losses upstream
from Whitewater will be more difficult because of extensive
modification of Streamflow by irrigated agriculture and the
much longer distances involved.
Description of Study Area
The study area is the approximate 12-mile reach of the
Gunnison River from the Whitewater station downstream to the
Redlands Canal diversion dam, which is about 3 miles upstream
from the confluence with the Colorado River (fig. 1). The
Redlands Canal (properly named "Redlands Power Canal," but
commonly, and in this report, referred to as "Redlands Canal")
has operated since about 1906, but the existing dam was built in
1917. The primary purpose of the canal is for power generation,
but some of the diverted water also is used for agricultural irri-
gation.
Elevations along the river range from about 4,560 feet at
the below-Redlands-dam station to about 4,630 feet at the
Whitewater station, but elevations are about 400-600 feet
higher on top of the canyon walls that are along some parts of
the study reach. Precipitation rates are typical of the grid to
semiarid climate and average about 9 inches annually
(Western Regional Climate Center, 2004). Rangeland (mixed,
herbaceous, and shrub and brush) and forest (evergreen, mixed,
and deciduous) predominate the high-desert landscape,