8018

• UCREFRP Catalog Number: 8018
• Author: Irving, D. B. and B. D. Burdick.
• Title: Reconnaissance Inventory and Prioritization of Existing and Potential Bottomlands in the Upper Colorado River Basin 1993-1994.
• USFW Year: 1995.
• USFW - Doc Type: \
• Copyright Material: NO

sites. It was unfortunate, however, that high runoff flows were not available
in 1994 to accurately predict the stage vs. discharge relationship. A larger
data base is needed to more accurately verify the predicted stage vs.
discharge relationship for the upper end of the May and June hydrograph. This
is especially important when estimating the magnitude, frequency, and duration
of flows necessary to flood a bottomland site.
Table 5. Range of flows and dates that stage-discharge data were collected in
the Green River drainage, 1994.
Maximum

Site 1994
Flows cfs Dates
MM DD Discharge (cfs)
1994 1993

Meril Snow 2,834-11,068 5/13-6/17 11,068 20,000
Ranch
Little 2,834-11,068 5/13-6/17 11,068 20,000
Stewart Lake
Baeser Bend 2,110-11,068 5/12-6/28 11,068 20,000
Johnson 4,443-11,068 5/11-6/14 11,068 20,000
Bottom Pond 2
Leota Bottom 3,645-11,068 5/11-6/15 11,068 20,000
Pond 7
Sheppard 3,645-11,068 5/12-6/15 11,068 20,000
Bottom Pond 3
Woods Bottom 2,110-11,068 1 5Z12-6Z28 11,068 20,000
Channel Cross Sections. Channel cross sections at each of the seven
bottomland sites were conducted in August, September, and October (Figures 8-
14). The river channel widths ranged from 127 to 794 feet (39-242 m) and the
bottomland sites ranged from 950 to 4,381 feet (290-1,335 m). The widest
wetted cross section was at Johnson Bottom (4,381 feet [1,335 m]) and the
narrowest cross section was at Baeser Bend (950 feet (290,m]) on the Green
River.
Using the stage vs. discharge and flow-frequency data (Appendix I;
Figure I.1.), the flow necessary to flood the particular bottomland
(floodplain depression) for all seven sites was estimated (Table 6; Figures 8-
14). For example, at the'Meril Snow Ranch site (Green River rm 303.0 [rkm
487.6]) we estimated the floodplain depression would flood at about 14,000-
15,000 cfs; these flows that might be experienced about one year out of three
to four (since 1966). However, this site requires validation of the stage vs.
discharge relationship because the correlation coefficient was the lowest of
the seven sites (r2=0.64). Re-establishing a staff gauge and obtaining
another data set during runoff at all seven sites is necessary to refine the
34