9605

• UCREFRP Catalog Number: 9605
• Author: Schmidt, J. C. and e. al.
• Title: Flow Recommendations for the White River, Utah-Colorado Draft Report.
• USFW Year: 2002.
• USFW - Doc Type: Logan, UT.
• Copyright Material: NO

the periods between September 15, 1967, and October 3, 1979, and between October 29,

1985, and September 30, 1997. Discharge measurement notes include channel depth and

width, as well as the location of the measurement in relation to the gage. These records

provide documentation of long-term changes in channel geometry and seasonal

fluctuations in bed elevation. At low discharges, measurements typically were made

with a wading rod within 75 meters up or downstream from the gage. At higher

discharges, measurements were made with a sounding weight suspended from the

cableway located at the gage. Actual discharge measurements were made approximately

twice each month during the period of time while the gage was maintained, and were

used to establish a stage-discharge rating relation. Measured discharges, cross-sectional

area, mean depth, maximum channel depth, and distance of the measurement from the

gage were transferred from the records into a spreadsheet and analyzed.

The bedelevation of the thalweg was calculated by subtracting the maximum

depth during a discharge measUrement from the stage elevation at the time of

measurement. All elevations were adjusted to a common datum for comparison. The

temporal sequence of thalweg elevation through time was compared to the record of

mean daily discharge. We analyzed the response of the bed to changes in discharge, and

we attempted to determine the discharge that caused scour and fill of the bed. Depth was

only recorded during direct discharge measurements, so the resolution of bed elevation

data was relatively low (approximately two per month) compared with published daily

gage measurements of stage elevation. Because of this low resolution, it was not

possible to determine precisely at what discharge the bed began to scour in each year

directly from the records. However, a decrease in thalweg elevation between two

.

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