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Colorado River Drainage
<br />Stage vs. Discharge Relationship. Nine staff gauges were installed at
<br />nine different bottomland sites during mid-May and monitored for approximately.
<br />45 days to obtain stage vs. discharge information for flows during the high-'
<br />flow period (Figures 15-22). Information for one site (Pike's, Colorado River
<br />rm 179.1 [rkm 288]) was not useable because livestock repeatedly disturbed the
<br />position of the camera; at two other sites (Griffith's, Colorado River rm
<br />176.0 [rkm 283]) and Clifton Sanitation No. 1., Colorado River rm 178.5 rkm
<br />287]) the period of time information was collected was prematurely terminated
<br />because the cameras were stolen. Spring runoff in the Colorado and Gunnison
<br />rivers was moderately low in 1994 compared to 1993 which was considered a
<br />moderately high year. The maximum daily mean discharge recorded during 1994
<br />for the Colorado River at the Stateline USGS gauge was 13,700 cfs on 2 June,
<br />whereas in the Gunnison River the maximum daily mean discharge at the
<br />Whitewater gauge was recorded at 6,040 cfs on 23 May. In 1993, the maximum
<br />daily mean discharge recorded for the Colorado River at the Stateline gauge
<br />was 44,000 cfs; in the Gunnison River the maximum daily mean discharge was
<br />20,500 cfs.
<br />Empirical stage data were collected over a narrow range and at a lower
<br />magnitude of flows in 1994 compared to previous higher water years (Table 7).
<br />Flows in 1994 were lower than anticipated to obtain a reliable stage vs.
<br />discharge relationship.
<br />Table 7. Range or flows and dates that stage-discharge data were collected in
<br />the Colorado and'Gunnison river drainages, 1994.
<br /> Maximum
<br />
<br />Site
<br />Flows (cfsZ Date
<br />MM DD Discharg
<br />1994 e (cfs)
<br />1993
<br />Johnson Boy's Slough 1,441- 6,040 5/16-7/ 7 6,040 20,500
<br />Confluence Park 2,708- 5,054 5/ 9-6/ 4 5,000 15
<br />400
<br />Adobe Creek 7,540-13,700 5/12-6/13 13,700 ,
<br />44
<br />000
<br />30-29 Road 5,511- 8,619 5/16-6/ 2 8,930 ,
<br />25,900
<br />Griffith' 3,974- 9,022 5/12-6/14 9,022 25
<br />900
<br />Clifton San. No. 1 5,698- 7,068 5/13-5/31 8,930 ,
<br />25
<br />900
<br />Pike's
<br />EXXON No Data --- 8,930 ,
<br />25,900
<br /> 4,424-11,000 5/17-6/ 3 11,000 22,200
<br />Battlement Mesa 6,419-11,000 5/17-6/ 8 11,000 22,200
<br />The linear regression correlation coefficients (r2) were high (range of 0.84
<br />to 0.98) for stage vs. discharge relationships at five of the eight sites.
<br />However, it was unfortunate that high runoff flows did not occur in 1994 to
<br />accurately predict the stage vs. discharge relationship. Additional empirical
<br />data are necessary to more accurately verify the predicted stage vs. discharge
<br />relationship for the upper end of the May and June hydrograph This
<br />information is even more important for estimating the magnitude, frequency,
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