7799

• UCREFRP Catalog Number: 7799
• Author: Modde, T. and D. Irving.
• Title: Conceptual Management Plan for Habitat Enhancement In Old Charley Wash.
• USFW Year: 1994.
• USFW - Doc Type: \
• Copyright Material: NO

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elevation the bottomland could be inundated by flows measured at Jensen as low as 14,000 cfs (Figure 3,

flow data provided by George Smith, USFWS). This is 3,000 to 6,000 cfs lower than estimated by Cooper

and Severn (1994) in the absence of contour elevation data. The elevation of the inlet to Old Charley Wash,

4,651 fas!. The estimated minimum water discharge required to enter Old Charley is estimated to be 8,500

cfs. Little historic data exists on the length of time water is retained in Old Charley Wash, however, last year

following a relative high flow year (spring peak exceeding 20,000 cfs) water was retained in the bottomland

through September. Cooper and Severn (1994) suggested the water elevation of Old Charley Wash is

closely correlated with water elevation in the Green River. Evaporation rates of the wetland are estimated

to be 2.5 feet between July and October.

Cooper and Severn (1994) described Old Charley Wash as a sodium-calcium sulfate-bicarbonate

type water (chloride occurs in low concentrations compared with sulfate and bicarbonate). Water

conductivity was relatively low compared to other waters sampled on the Ouray National Wildlife Refuge with

most open water measurements ranging between approximately 300 and 600 umhosjcentimeter. Dissolved

oxygen ranged between 2 and 11 ppm in July and August. Several other chemical variables were measured

by Cooper and Severn (1994) and none appeared to be of biological concern. Water samples were tested

for selenium but concentrations were not detectable. Currently, Old Charley Wash has a water control

structure on both the inlet (elevation 4,651 fasl) and the outlet (4,646 fasl). A fish access control structure

was built into the outlet structure last fall. This spring, grading will be completed in Old Charley Wash to

allow contour draining of the bottomland. The water control structure at the inlet is currently operable, but,

needs to be repaired if it is to be used on a regular basis in the future.

Because Old Charley Wash is connected to the Green River at flows exceeding 14,000 cfs, the fishes

found in this wetland are identical to those occupying the Green River. In 1986, Tyus and Karp (1990)

reported 20 razorback sucker were collected from the outlets of Stewart lake and Old Charley Wash.

Colorado River Fish Project data records indicate that 42 adult razorback sucker have been collected

between Green River miles 251 and 248 between 1980 and 1992. Colorado squawfish adults implanted with

radio transmitters have also been observed occupying Old Charley Wash (Tyus and Karp 1991). In addition,

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