7415

• UCREFRP Catalog Number: 7415
• Author: U.S. Fish and Wildlife Service.
• Title: Flaming Gorge Peaking Power Study-Preliminary Draft.
• USFW Year: 1988.
• USFW - Doc Type: Denver, Colorado.
• Copyright Material: NO

.Significant changes occur in the release hydrograph pattern in
this reach of the river. The model parameters were adjusted
until the observed conditions at the Gates of Lodore were
adequately simulated.
In 1985, endangered species and recreational concerns prompted
the extension of the model calibration down to the USGS gage at
Jensen, Utah, with intermediate calibration checks at Hell's Half
Mile, Jones Hole, and Rainbow Park. Staff gage readings only
were taken at these intermediate points, while the actual flow
readings at the Jensen gage were used in the calibration. The
results of this model were used to evaluate the impacts of
proposed endangered species flows during August and September.
Graphs included in the 1987 Environmental Assessment for the
Recovery Implementation Plan were taken from routings performed
using this model. From a recreation perspective, this model also
provided insights into the specific results of increasing the
minimum night-time releases from the dam.
Echo Park to Tia Juana Bottom
During November 1987, a week was spent calibrating and validating
the SSARR Model from Echo Park to the Ouray Refuge. The
calibration process consisted of establishing the network
displayed in Figure 1, and selecting a calibration period when
data was available from all the USGS gages and the Service
operated recorders. Initial calibration of the Echo Park to
Ouray Refuge reach was based upon having good recorder data at
both sites from October 7-21, 1987. Based upon this period,
information from the recorder strip charts, rating tables and
USGS gages was then input to the SSARR at Mitten Park, Jensen and
the Ouray Refuge. The calibration was accomplished by comparing
observed flows at each site with computed flows at each site, and
adjusting travel times and model coefficients to align the peaks,
and to adjust attenuation of the peaks. The model was considered
calibrated at a site when the observed and computed time series
plots matched within 3 hours and the flows coincided within 20
percent.
Further calibration work was undertaken in July of 1988 when data
for the Tia Juana Bottom site was added and additional points
were added to the Mitten Park and Ouray Refuge rating tables.
Ouray Refuge
Figures 6-8 display graphically the results of the calibration'
process at Ouray Refuge. The figures show a typical peaking
release from Flaming Gorge and the attenuation that takes place
by the time the water reaches the Ouray Refuge site. The results
of the calibration indicated that travel time from Flaming Gorge
to ouray is 56 hours, and the maximum change in stage from trough
to peak is 1.45 feet when peaking flows range from 800 cfs to
4200 cfs. Tables 4 and 5 display similar results for each of the
sites that are currently calibrated based upon differing releases
from Flaming Gorge.
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