8246

• UCREFRP Catalog Number: 8246
• Author: Schmidt, J. C.
• Title: Compilation of Historical Hydrologic and Geomorphic Data for the Upper Colorado River Basin.
• USFW Year: 1994.
• USFW - Doc Type: Flaming Gorge Research Program Study No. 37,
• Copyright Material: NO

I

INTRODUCTION
River hydrology and geomorphology provide the physical template within which
the endangered fish of the Upper Colorado basin have evolved. Development of
management objectives and operational rules for large dams must in part be based on a
precise and accurate understanding of the physical changes that have occurred along the
basin's large rivers. Since climatic and land use changes have occurred during the past
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entirely due to the existence and operations of large dams. Analysis of historical changes
provides a perspective on the role of large dams, in relation to other factors, in causing
the observed changes. The purpose of this report is to summarize data collected during
1994 which are the basis of forthcoming analyses of historical changes.
PROJECT ORGANIZATION
Project activities in 1994 were focused on the following:
1. synthesize existing long-term gaging station records and estimate annual peak
flows for short-record stations on the Green River so as to develop a standardized base
period from which hydrologic changes can be analyzed throughout the river system;
2. analyze gaging station stream gaging notes and develop hydraulic geometry
relations and time series data of channel cross-section and ice cover changes;
3. obtain and interpret aerial photography of the river corridor as it existed at
the time of closure of Flaming Gorge Dam (1963) so as to provide a basis for
comparisonwith present conditions along the river;
4. obtain, match, and interpret oblique photography to establish the extent of
geomorphic change along the Green River in different reaches since the 1880's;
5. develop a comprehensive geomorphic data base for the Green River.
METHODS
Flood record analysis (Appendix A)
The common base period established for Colorado basin gages begins in 1923. By
this time, all of the long-term gages had been established. Stations at Green River, WY,
and Green River, UT, had been established in 1895, but stations of other rivers were not
yet established. Flood records for the stations near Greendale, UT (09234500), and
near Jensen, UT (09261000), were extended by correlating these records with those of
the nearby longterm stations.
The records of the gages near Greendale, UT, (1950-present) and near Linwood,
UT, (09225500) (1929-1963) overlap. A linear correlation between the two records
has an r2 value of 0.944 and was used to extend the Greendale record to 1929. A
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