7993

• UCREFRP Catalog Number: 7993
• Author: Mabey, L. W.
• Title: Planktonic and Benthic Microcrustaceans from Floodplain and River Habitats of the Ouray Refuge on the Green, River, Utah - Master's Thesis.
• USFW Year: 1993.
• USFW - Doc Type: Brigham Young University,
• Copyright Material: NO

Study Sites
Our study sites included three representative habitats: backwater, river channel,
and seasonal floodplain. The sites were located along the Green River at river km 404
on the Ouray National Wildlife Refuge (Fig. 1 and 2) near the town of Ouray, Uintah
County, Utah, U.S.A. The Green River at the U.S.G.S. gaging station near Jensen
approximately 77 km below the confluence with the Yampa River has a drainage area
of 47,723 km2. The historical flows of the Green River have been altered by dams.
These changes in natural flows and diking along the river has changed the severity
and frequency of flooding. The Yampa River joins the Green River 155 km upstream
of our study site. The Yampa River is the only large river in the area that remains
undammed and the Green River below its confluence still floods occasionally. The
average pre-impoundment flows on the Green River from 1946 to 1961 ranged
between 460 cros (16,238 cfs) and 50 cros (1,765 cfs). Since impoundment by
Flaming Gorge Dam in 1962, high flows have been reduced 27% to 335 cros (11,926
cfs) and the low flows have increased 200% to 100 cros (3,530 cfs) (U.S.G.S. data).
The highest flow ever recorded on the Green River near Jensen was 1133 cros
(40,000 cfs) on May 18, 1984.
Backwaters
Two backwaters were sampled. Intersection Wash only existed at high water and
was isolated from the main river channel at low water. The site was at the mouth of
an intermittent tributary that only carried water during spates. The Ouray backwater
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