WSP09117

• File Number: 8102
• Description: Arkansas River Hydrology
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 10/1/1970
• Author: Colorado DNR
• Title: Preliminary Report on Travel Time and Transit Losses Arkansas River October 1970
• Water Supply Pro - Doc Type: Report/Study

DJJ199

28

of the wave front could be plotted.
before, during, and after the stage
tions were made as to the character
were collected.

The river temperature was also monitored
increase. In addition, general observa-
of the river channel and water samples

The increase in river stage due to the translatory wave was abrupt in
the Arkansas River from Twin Lakes to the Hobson gage east of Florence. The
abrupt stage increase in this section of the river occurred over only 5 to
10 minutes of time; however, the stage increase at Pueblo took nearly I 1/2
hours. In most places, this stage increase was from 1 to I 1/2 feet except
in places where the river was wider ,and there a stage increase of 1/4 to 1/2
foot was observed.

Two of the temporary river stage stations were below the Colorado Canal
and were used to determine if there were noticeable changes in the river past
the point where the reservoir run was turned into the Colorado Canal.

AIJALYSIS

The time of travel of water in the Arkansas River is dependent on the
stage of the river, which is directly related to the flow in the river. At
low stages the travel time is greater than when the river is at a higher stage
or higher flow. The natural flow varies greatly from the reservoir to where
it is being diverted, oftentimes the natural flow increases from 100 cfs at
Granite,to 900 cfs or more at Canon City. The flow at Canon City was used
as an index of the stage, or flow, of the Arkansas River from Twin Lakes to
the Colorado Canal. This station was chosen because it is near the center
of the study reach, it is above the major diversion points, it has a long
record and can be easily used in administration since it is a telemeter
station and can be "read" anytime from anywhere. The mean annual flow at
Canon City is about twice that of Granite and about the same as Pueblo.
Other stations were studied for possible use as an index, but were not as
satisfactory as Canon City.

Travel time for the front of the release and the shutoff of the release
was plotted against the natural flow at Canon City, that is, the flow before
the release and after the release, respectively. The travel times were also
plotted against the total flow at Canon City just after the release first
passed Canon City and just before shutoff. It was found that the higher flow,
that is, the flow including the reservoir water, gave more consistent results.
Figure IV-l uses the flow at Canon City, after the release, as an index for
the stage for the front of the wave. In practice, the administrator could
add the natural flow at Canon City to the release rate so that he could use
the nomograph to estimate the travel time before the release was made. The
flow at Canon City just before the shutoff is made is used as the stage index
for estimating the time it takes the shutoff to be felt at the Colorado Canal.

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Using the index flows described above, it was found that the release wave
took an average of six hours more time to reach Pueblo than did the first
effect of the shutoff. The velocities of the release wave and shutoff effect
were very similar below Pueblo. The salient features of various river hydro-
graphs were followed from Granite and Pueblo, when plotted on Figure I,
generally plotted near the release curve. This tends to verify the accuracy
of Figure IV-I.

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