9493

• UCREFRP Catalog Number: 9493
• Author: Gaeuman, D., P. R. Wilcock and J. C. Schmidt.
• Title: High Flow Requirements for Channel and Habitat Maintenance of the Lower Duchesne River between Randlett and Ouray, Utah.
• USFW Year: 2003.
• USFW - Doc Type: \
• Copyright Material: NO

FINAL REPORT, November 2003
High-flow Requirements for the Duchesne River

DESCRIPTION OF THE STUDY AREA

The Duchesne River drains most of the Uinta Basin, a broad structural and topographic
depression between the Uinta Mountains and the Tavaputs Plateau in eastern Utah. All of the
Duchesne River's tributaries that have significant stream flow have their headwaters on the south
slope ofthe Uinta Mountains. These tributaries flow in a southerly direction and join the
Duchesne River on the south side of the Uinta Basin. The Duchesne River itself flows east and
southeast along the basin axis. Its confluence with the Green River is at Ouray, Utah (Figure 1).
The east-flowing portion of the river traversing the Uinta Basin is incised into Tertiary
sandstones and shales. Remnants of Pleistocene outwash plains form scattered benches 100 to
200 m above the present river level (Osborn 1973).
The Duchesne River and its tributaries have been impacted by water development projects,
including trans-basin tunnels that divert water to the west slope ofthe Wasatch Range. The
Strawberry Tunnel began diverting up to 60,000 acre-feet per year of Uinta Basin water out of
the basin in 1915. A second trans-basin tunnel, the Duchesne Tunnel, started diverting an
additional 37,000 acre-feet annually in 1954 (Brown 1991). Currently, continued development
of a system of reservoirs and canals known as the Central Utah Project is intended to deliver
additional stream flow from a number of Duchesne River tributaries to Strawberry Reservoir and
on to the Wasatch Front. As described in this report, reduced stream flow as a result of these and
other development projects has altered the geomorphology of the alluvial valley and channel of
the Duchesne River and has the potential to playa role in the loss of native fish in the upper
Colorado River basin.
The lower Duchesne River extends from the mouth of the Uinta River near Randlett, Utah,
to the confluence of the Duchesne with the Green River 27 km downstream (Figure 1). The
reach extending 4 km upstream from the Green River has been designated as critical habitat for
razorback sucker (Xyrauchen texanus), an endangered native fish species (Fed Reg.NoL 59, No.
54, March 21, 1994). Razorback sucker and another endangered native fish, the Colorado
pikeminnow (Ptychocheilus lucius), have been documented to utilize habitats at the mouth ofthe
Duchesne River (Modde 1997), and Colorado pikeminnow have been observed in areas
throughout the lower 24 km of the river (Duchesne River Fisheries Study Progress Report:

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